The Sentinel

by Geoff Crammond, Mike Follin, Tim Follin, David John Rowe
Firebird Software Ltd
Crash Issue 40, May 1987   page(s) 20,21

Producer: Firebird
Retail Price: £9.95
Author: Geoff Crammond

Absorption, says the dictionary, is a process whereby one object disappears through incorporation in something else; a sucking in of fluid, light or nutriment. It also means a mental engrossment - and generally, that is the aim of any good game. In The Sentinel, FIREBIRD have pared absorption to its most elemental components, and produced a game which they hope is absorbing, and is about absorbing.

Think of 10,000 planets, merely a fraction of the known universe, but almost infinite by man's reckoning. 9,999 of these worlds are under the sway of a supremely powerful malignant being - The Sentinel. What it is, or what its purpose might be, no one knows. What it does, however, is well understood. The Sentinel has slowly but inexorably travelled through the galaxy, absorbing the energies of all the worlds it touches upon, leaving on each one an image of itself and, on some levels, a host of attendant Sentries.

Now it is Earth's turn. There is hope, though. The Sentinel can be attacked by reversing the process, and absorbing energy from it - world by world. The struggle is elemental - you against the Sentinel in a battle of wits played out on a 3D landscape where the chess pieces are your robots, boulders, trees, sentries and units of raw energy.

Where to begin? Any of the worlds may be chosen, as long as you have attained its entry code, thus you are forced to play planet by planet, and you are hyperspaced down to its surface. An aerial view is displayed, showing the relative positions of the Sentinel and its Sentries, before you are placed on the surface. The Sentinel always occupies the highest point of the landscape, you are transported to the lowest. Look around for a while, get the feel of this world. Until you start absorbing or expending energy, your enemies will remain inactive.

When you do, The Sentinel and its Sentries begin scanning the landscape, searching for squares containing more than one unit of energy - that's likely to be you. If they can clearly see the square on which you stand, then they reduce its energy level by one unit at a time, creating a tree somewhere else in the process. In turn you can absorb the energy units of objects on the landscape, such as trees or Sentries, or even The Sentinel itself, as long as you can centre on the square they stand on, and then use that energy to create new objects.

The point of this is to make new robots for yourself, transfer to the waiting robot, and then absorb the energy of the robot you have just left. In this way movement around the landscape is possible. Boulders can be stacked up to create higher vantage points for observing and attacking the positions of Sentries and The Sentinel.

A clear strategy is essential. You must hide from the absorption potential of the enemy, yet at the same time manoeuvre into positions of attack. Sometimes the action becomes frenzied. If a Sentry or The Sentinel can see the square you are standing on, a screen scanner warns, and there are five seconds to move before your energy is absorbed. Should the enemy see you, but find your square obscured by landscape, the scanner warns again, then a tree in a better vantage point for the job is transformed into a Meanie to flush you out of hiding. The Meanie rotates rapidly until it can see you, then forces you to hyperspace to a new random location, but probably one not to your liking.

Hyperspacing costs energy units, because the Meanie creates a new robot, transfers you to it, but leaves the old one behind, wasting energy. You may be able to re-absorb it later, however, if it hasn't already been absorbed by The Sentinel.

Gaining fluency with the control of your circumstances is vital for those moments when all hell breaks loose. The view may be panned up or down, left or right through 360°, or snap-turns can be made. A sight may be turned on so that absorption, creation or a transfer may take place. And there are separate controls for creating trees, robots or boulders.

If you manage to defeat The Sentinel by absorbing all its energy, transfer to its position, the highest spot on that world, and hyperspace. You are given a new entry code for another world, another battle, another Sentinel.


Control keys: S/D pan left/right, K/M pan up/down, A to Absorb, T, B and R to create Trees, Boulders and Robots respectively, H to Hyperspace, Q to Transfer
Joystick: Kempston, Interface 2, Cursor
Use of colour: monochrome effect, but background colour-change option
Graphics: excellent line and cross-hatched shading creates solid 3D, the whole scrolling smoothly and fast
Sound: some tunes and limited but effective spot FX
Skill levels: effectively, you make your own
Screens: 10,000 landscapes

This is a completely original concept, which has been superbly implemented to produce one of the best computer games ever. It's deceptively simple, but, like Chess or any other game of a similar nature, an awful lot of thought must come into play to succeed in the higher levels. The gameplay is jam-packed with atmosphere and nail-biting tension that's sure to keep you enthralled for a long time. The Sentinel looks surprisingly good; the landscape is excellently shaded - clear, uncluttered and with superb scrolling. Sound effects and tunettes are of a high standard, but it's a shame that there aren't a few more. This is state-of-the-art software. Buy it.

The Sentinel seems appears complex to an onlooker, yet it's fiendishly simple. The landscape may look straightforward, but until you discover The Sentinel's whereabouts and the location the computer sends you to, you'll never know the real task which lies ahead. The fun of The Sentinel is the clever mix of occasions when you're frantically pressing all buttons in the hope of escape, and other times when slow, deep thought is needed to find an ideal place to attack from. The addictive qualities are increased greatly by the codes, meaning that you can come back to it months later and still go to the landscape where you left off, without having to go through the same old screens over again. The Sentinel defies all adjectives.

They told me it would be good, but I didn't expect anything like this. The Sentinel is brilliant. It's a weird sort of game, not a shoot 'em up, more an absorb 'em up. The concept is not remotely like anything I've ever seen before, and one that is magnificent. If the graphics are jerky, the shading and the change colour option make up for that ten times over. The Sentinel is so playable that you go into it for the first time and come out in a trance!

Presentation: 90%
Graphics: 93%
Playability: 98%
Addictive Qualities: 96%
Value For Money: 95%
Overall: 97%

Summary: General Rating: Highly playable and addictive, The Sentinel is one of those rare games that makes owning a computer a delight.

Award: Crash Smash

Transcript by Chris Bourne

Your Sinclair Issue 18, Jun 1987   page(s) 84,85

What's got 10,000 screens, hordes of vicious robots out for your blood, and a zillion complex puzzles for you to solve? We drop Phil South into Firebird's Sentinel to see if he's king of the castle!

Game: The Sentinel
Publisher: Firebird
Price: £9.95

It's dark. All you con see is the wall of a high computer-generated cliff. As you rotate on the spot, you can see a small clump of trees, which you quickly absorb for their energy. You can't see any more without tilting your head... then as you look up you can see it, its slowly rotating body towering over you. All too soon its malevolent eye turns on you, and you start to feel the energy being sucked from your body. Finally, as your consciousness blinks out, you see the face of your destroyer... the evil Sentinel. Oh well, better luck next life.

It's rare than an original game concept comes out, so when one appears it takes you completely by surprise. Sentinel is just such a game. It's a new kind of strategy/arcade idea, which draws from elements common in a range of traditional strategy formats. It takes place in stunning 3D renderings of 10,000 different landscapes through which the player moves, (or more precisely, teleports) in his quest to destroy the evil Sentinel. Yes, you must destroy him... but the catch is that if he sees you, he'll absorb your energy and you're dead!

On each landscape there's a finite amount of energy to be had, in the form of trees which are dotted around the computer generated hills and valleys in a more or less random way. You have to absorb the trees to get any goodness out of them. Having gained a bit of energy, you can then project it out of your robot body, by creating something tangible, like another tree, a boulder or a fresh robot. Now, and here comes the clever bit, you can teleport yourself (accompanied by a digitised riff from a synthesiser, a sort of Whaaanggg!) into that new robot body and absorb the one you just left, and in this way you move across the landscape. The reason you absorb the robot you just left is because the amount of energy remains constant in the landscape - so if you expend energy to make a new robot, you must gain some of that energy back by absorbing your old robot. As to why you need as much energy as possible, we'll go into that in a minute.

Your view of the computerised landscapes appears as if you're looking out of the head of the robot. You're able to pan round to look for the Sentinel and, using the crosshaired sight, orient on and absorb trees. This may all sound a bit easy-peasy to you, but there's one major point to the gameplay which prevents you from just scooting around, teleporting wherever you please and eating every tree you can see. You can't absorb anything unless you can look down on the square the object stands on, and that goes for boulders, trees, your robots and even the Sentinel itself. If you can't see it, you can't eat it! This can be very frustrating if you can see the top of a tree but can't see the square it's standing on. (The secret is to always go for extra height, but we'll get to that later!) Once you've managed to absorb the Sentinel and climbed up to where he was standing you can hyperspace to the next level. Here's another clever bit - depending on the number of points you have left when you've absorbed the Sentinel, you go on to a higher level. The more points, the higher the level. The entry code for the level you've achieved is displayed across the sccreen and you type this in when asked for it. And if you write it down on a bit of paper, you can go straight to that level next time you play and so save yourself the worry of going through from level one again.

The graphics are totally brilliant, being by far the best 3D effect I've seen on the Speccy, and the digitised or sampled music is great. It sounds like that spooky synth music you used to get in Dr Who. (Daaann dannn dannnnnn! Ooooooo!) Soo-parb!

If you find this all a bit hard to grasp, and who could blame you, don't worry. We've constructed a little Sentinel universe in microcosm, from which you should be able to draw all the conclusions you could possibly want. So sit back, and we'll take you forth into the dangerous realm of... (deep voice) The Sentinel!

Graphics: 9/10
Playability: 9/10
Value For Money: 9/10
Addictiveness: 9/10
Overall: 9/10

Award: Your Sinclair Megagame

Transcript by Chris Bourne

Your Sinclair Issue 57, Sep 1990   page(s) 66

Cripes! You'd better look sharpish 'cos here comes...


Yep, readers, looks like it's time once again for another one of those Complete Guide thingies. This issue, for your delight and delectation, we thought we'd take a peek at the more puzzley sort of games. Y'know - puzzle games - those sort of weird ones where you have to use a bit of the ol' grey matter to solve, erm, puzzles and things. And who better to clasp you by the hand and drag you through the world of the mind-boggling than YS's resident 'heart-throb' RICH PELLEY. Hurrah!


As usual, the normal rating system seems a bit crap in these circumstances, so here's a different one instead.

How complex and difficult to finish are the puzzles? Are they a complete bummer to complete, or could you do it with your little finger stuck, er, wherever you want to stick it?

Will it have you coming back for more (and more) or will a few games be enough? (Who knows?)

Is the game easy to get into, or do you have to spend ages looking up various keys, and working out what's going on all the time? (The lower the mark the better the gameplay in this case.)

Are the puzzles varied, or are they all the same? (Er, obvious, really.)

Okay, so I admit it - I'm crap at puzzle games. Come to think of it, I'm crap at most games really. And I'm not in a particularly good mood today either 'cos I've got a sneaky suspicion that this guide thingy is going to take absolutely ages to write. Even though Matt has reassured me "It won't take long" and Jonathan has informed me (much to my surprise) that "Honest, it'll really be a lot of fun to do" I'm a little dubious. Still, let's get on with it and see what happens, shall we?

For a start, I can see one big problem staring me in the face almost immediately. I mean, what exactly makes a puzzle game a puzzle game, eh? One man's puzzle game may another one's arcade adventure be or, um, something really. We've had countless arguments here in the office over it already (and for some reason I always seem to lose). For instance, Matt thought Arkanoid, Batty and the like might almost count, while Jonathan firmly disagreed. (In fact, if Jonathan had had his way, Tetris would be 'the only true puzzler ever written' and this would be the shortest Complete Guide on record!) Seeing as this is my feature though, and I'm writing it, everybody's going to have to agree with me!

And what is my definition? Well, it's fairly loose really. It's anything where you have to try to work out some sort of (perhaps totally abstract) mental problem against a time limit. Most great puzzle games are based on one very simple initial idea, which is then perhaps spiced up by slicking in lots of different ways that you can earn bonuses, die, get extra weapons or abilities (if it's a weapons sort of game) and so on. It's the simple initial idea that really counts though - if you haven't got that, you ain't got much really.

So what sort of puzzle games have we got here, then? Well, lots of different ones really - there are games where you must arrange blocks, make pictures, blow up balls, collect keys, and do masses more equally weird and wonderful puzzley things.

One good thing though is the scope - unlike in most areas of Speccy programming, with puzzle games you sometimes actually get a degree of originality. The games I've covered here are all good ones, and all still fairly easily available and - would you believe it? - no two of them are the same! (Well, no three of them at least.) And, erm, cripes, looks like I've run out of things to say. So, um, I'll stop waffling and get on with it, shall I?


Um, er, um. Now you re asking. Turning to the very first issue of Your Spectrum (ie Your Sinclair in disguise), I find one lurking in the first few pages. Traxx from Quicksilver is its name, and what seems to happen is that you move around this little grid thing collecting squares. Fun, eh? (Alright, I admit it. Of course there's no way that could be the first commercially available puzzle game, but it's the first I could come up with. Sorry and all that.) Anyway, on with the show.

NB Erm, actually, before we start, I'd just like to clear something up. You may notice that all the marks for the following games are quite high - there don't seem to be any crap ones. Now this isn't 'cos I'm a great puzzles fan or anything (in truth I hate them all) - it's just that unfortunately all the ones I've picked have been quite original and good. And keeping up my reviewer's credibility, I have to be fair. Hence the high marks.

The Sentinel
Reviewer: Rich Pelley

Er, um, so okay - it's not really that much of a puzzle game, but I'm desperately running out of the things. So just pretend it's not here or something.

Anyway, The Sentinel, eh? I'm pretty sure (I wouldn't take my word for it, though) that it was the first solid 3D game on the Spec. And what happens is that you're this robot thingy, and there's this sentinal thingy way above you who turns around slowly. If he looks at you then you start dying, so you must climb up to his level by creating rocks and trees and things. and eventually absorb him. This may all sound very complicated, but once you've got into it, it really is lemon peasy and very enjoyable into the bargain, despite the large pauses during play which do tend to hinder things a bit.


There we have it! As I predicted (and Matt and Jonathan got totally wrong) it took me absolutely blooming ages. And most of that time was spent arguing about what a puzzle game actually is and what qualifies and what doesn't (which is one reason why we don't have a giant list of all the ones ever made - we just couldn't agree what they were!).

Next month - Flight Sims. (Something everyone can agree on.) Hurrah!

Fiendishness: 90%
Lack Of Sleep Factor: 60%
Pull Your Hair Out Factor: 30%
Variation: 78%
Overall: 79%

Transcript by Chris Bourne

Sinclair User Issue 62, May 1987   page(s) 24,25

Label: Firebird
Author: Geoff Crammond
Price: £9.95
Joystick: various
Memory: 48K/128K
Reviewer: Graham Taylor

Sentinel is very, very strange. It has won trillions of awards on other formats just for being extraordinarily peculiar.

The fact that it was technically brilliant and astonishingly addictive as well may have helped.

Imagine a cross between chess, What's the Time Mr Wolf?, recent developments in quantum physics and fractal landscape techniques. Bet that helps a lot doesn't it?

You're set down in this landscape. Actually it's one of around 16,000 possible landscapes! It's sort of craggy rocky affair not unlike the mountains of the moon or Herne Bay. Each craggy landscape consists of distinct levels - plateaux divided into a checkerboard of different squares at different levels. The only thing it reminded me of - and that not a lot - is Marble Madness, but with a worm's eye view.

Somewhere on one of the higher peaks in this landscape stands the Sentinel - a giant statue-like figure which slowly turns through 360 degrees. If you should get in a position where the Sentinel can 'see' you your energy instantly begins to drain. On harder levels the Sentinel has a bunch of sentrys that are also standing around looking for you. The game is this. If they see you and your energy drains to zero you get absorbed. If you sneak up on the Sentinel - get on a level higher than it and absorb it, you've 'won' that landscape.

The quantum physics comes in with the general principle that operates in the game that matter cannot be destroyed and there is a finite amount of energy in each universe. You use energy to move, you use energy to create. You can create trees, boulders or other selves. The opposite of creating energy is absorbing energy and this works in exactly the reverse way, ie. If you spot a tree or a boulder you can absorb it and gain energy. Movement is a matter of scanning around for a robot in that square and then transporting yourself to that square. Having transported yourself you can absorb your old body.

All this cosmic stuff shouldn't hide the fact that what you are really playing is a sort of hide and seek. You carefully move around the landscape looking for trees or boulders to absorb but without moving to a square from which you can be seen by the Sentinel or its Guardians.

The problem is where to move to that will both get you higher - nearer the Sentinel - yet not leave you exposed.

The game looks extrodinary, a little like those fractal, landscape games with clever use of shading and lines to give the impression of some alien but 'real' looking landscape. The Sentinel, guardians, trees and boulders are equally well, if simply, realised. Whatever else, you've never seen another game that looks like this one.

I managed to beat the first few levels relatively easily but the game soon becomes unbelievably difficult. Paranoia sets in as you start to wonder if there is a single place you can move to without being seen.

Your tactics get more subtle (well more subtle than just pressing the Hyperspace 'run away' button anyway). If you get close to the Sentinel you can tell which way it is turning (it must turn before it sees you) and plan your movements accordingly. You can also create some objects in squares to 'test' whether they can be seen or not - Sentinels will always absorb energy from any object they can.

Win through a landscape and you get a code for your next level. The more energy you have left means the higher the level you get the code for - so the better you did the faster you jump up the levels scale.

So it goes on. And so you'll go on. Rather than becoming repetitive this is an astoundingly addictive game.


Overall: 5/5

Summary: Unlike any other game, this is completely original. Technically staggering and frighteningly addictive.

Award: Sinclair User Classic

Transcript by Chris Bourne

ZX Computing Issue 38, Jun 1987   page(s) 40



In a land far away where pure energy is the only source of power the Sentinel rules supreme. Now you aim to challenge this master in a battle that will rage over 10,000 landscapes that are amazingly crammed into 48K!

Each landscape is a world of its own built out of plateaus, peaks and pits. On top of the highest peak stands the Sentinel. You begin at the bottom of the deepest pit.

The sentinel from it's lofty throne slowly rotates and scans the landscape beneath it for anything with a surplus of energy, such as you. The Sentinel absorbs the energy of living things and recycles it into the lowest life form which is a curious conical tree that it scatters around the barren landscape. You can absorb these trees to collect the energy to defeat the Sentinel.

You are in fact a robot that can't move but can duplicate robot shells from energy and transfer to them. You can then reabsorb the old robot shell thereby reclaiming the energy. Using this method you can move to any plateau you can see below you, and can rise up levels by building boulders on top of plateaus then the robot shell on top of that. You can stack boulders to any height (although you can only see the top of one boulder) and build up to the highest level. However, a boulder costs two units of energy and a robot three which tends to limit your excursions. If you think you're in desperate trouble you can hyper space (costs three units) but you'll end up at a equal height or even lower plateau.

If the Sentinel traps you in its deadly gaze it will gradually absorb your stored energy until you either transfer to another robot, hyperspace or die. If it spots you but can't see the base of the plateau you're standing on it will try to flush you out by converting the nearest tree into a meanie. These snake like creatures also rotate and if it sees you before you can absorb it or get away then it'll force you to hyperspace. This will cost you three units and will probably land you in the gaze of the waiting Sentinel.

By landscape thirteen things are getting a little trickier as the Sentinel has now recruited the help of a Sentry. This is a mini Sentinel that also stands on a tall peak and absorbs anything caught in it's gaze, creates Meanies to flush you out and of course guards the Sentinel. In later landscapes the Sentinel recruits more and more Sentries which must be destroyed before you can tackle the Sentinel. By now the landscape is also getting flatter with less cover in which you can hide from the energy draining gazes of the Sentinel and his Sentries. In one landscape you begin in the centre of a wide open circle surrounded by nine peaks containing the Sentinel and eight Sentries!

The game is a mixture of tactics, energy collecting and reactions as you escape Meanies and the Sentinel. Your first task is to find the Sentinel (for Sentry) before they find you and gauge the direction and speed that it's rotating. You can then aim to stay on its blind side while you absorb enough trees for your assault. To absorb the Sentinel and complete the landscape you must get above it (by standing on boulders and absorb it by homing in on it's base. One landscape down only 9,999 to go!

You don't actually have to complete every landscape as on completion of one you're given the eight digit code for your next one. The next code you're given depends on the amount of energy you have left once the Sentinel has been defeated. The more energy you have the more landscapes you skip. Soon you will have pages and pages of eight digit codes corresponding to the games landscapes. This means you can start any game at any landscape you like as long as you have the code. It's best to keep all the codes you find as you may get stuck on a particularly tough level that you could leap frog by redoing a previous level and aim to finish it with more energy.

The Sentinel is an absorbing mix of gameplay demanding strategy and skill to solve it. Original, addictive and massive, what more could you possibly want?

Award: ZX Computing ZX Monster Hit

Transcript by Chris Bourne

Crash Issue Annual 2018   page(s) 62

As the Crash annuals are still for sale ZXSR has taken the decision to remove all review text, apart from reviewer names and scores from the database. A backup has been taken of the review text which is stored offsite. The review text will not be included without the express permission of the Annuals editorial team/owners.

Transcript by Chris Bourne

All information in this page is provided by ZXSR instead of ZXDB