I first played the sentinel on the Amstract CPC6128 which was a slightly better version graphics wise than the original commodore game. It is a very odd strategy game - kind of close to a board game but I have never found anything like it for simplicity or concept since.
You are a robot on a hilly chequered landscape. You cannot move along but you can rotate, and create matter on any square that you can see - you can create trees (1 point), boulders (2 points) or other robots (3 points).
Once you have created another robot you can 'jump' into him and reabsorb your old one, provided you can see the square he's standing on.
Also on the board is the sentinel - he rotates slowly - with an audible click each time, and when he sees you he starts to suck away your energy points one by one, so when you are seen you need to move quickly out of his line of sight. Everything he takes away reappears on the board as trees and it is these you absorb to get more energy - kind of a one man deforestation exercise which might not have been the best lesson to teach the kids of the eighties!
The object of the game is to
climb high enough to see the top of the sentinels podium, absorb him, get on there yourself and hyperspace (once you've killed the sentinel you can no longer absorb anything else). The amount of energy points you have left are added to the level you are on and you are given the code to enter the corresponding level - there are 1000's.
On later levels there maybe 10 or more sentries, they are as dangerous as the sentinel but may be lower down - the game doesn't end when you kill them. Sentinels and sentries can also turn trees into 'meanies' if they can see you but not your square - you can absorb these too if you see them in time.
This game is utterly addictive and requires some thinking and strategy.
