What happens when one of those robotised factories floating around in space is no longer needed? After all, a man in Earth Head Office can hardly reach out to an instrument panel and press an 'off' button... for one thing the factories are over 100,000 light years away. Worse still, they were constructed with an in-built protection system, designed specifically to stop rival companies shutting them down. No. the only way companies can silence these obsolete hulks is by employing men like you (a freelance Robot Factory Deactivator) to roam the Universe in your compact space fighter, shutting them down as it becomes necessary.
Deactivating a factory involves the completion of three different tasks. First, the factory's automatic defence system has to be negotiated. The screen scrolls diagonally as the fighter approaches the factory and defensive mines home in kamikaze-style, attempting to destroy what they consider to be a hostile intruder. There are three back-up craft, one of which is lost if these mines strike home. The fighter moves left and right to avoid the onslaught, and shoot bursts of laser fire which destroy the mines. Travelling far enough into the defence system brings you to the factory where the fighter automatically lands.
Next the factory floor must be cleared of 'power dots', using a remote control drone. The screen displays a 3D forced perspective view of the factory's interior which scrolls as the drone moves along the power dot filled tracks. You can't fall off the path, but crashing into one of the drones trundling around the maze-like system loses another reserve craft. The dots are cleared by travelling over them, and when enough are eradicated, the score display flashes. The drone can then be moved to either end of the factory to complete the screen.
During the clearing period some of the dots are impossible to pick up - these form a pattern which must be remembered if the third and final stage is to be completed. A panel appears containing a series of buttons. Using these, the pattern revealed in the previous stage must be recreated. This is achieved by bouncing a suspended ball on the correct buttons. This task is made more difficult by a defence force field which slowly follows your movements across the slab - if the ball is dropped onto a button guarded by the force field, another craft is lost. A button can only be activated if it's flashing yellow - any other colour and the ball has no effect.
When this puzzle is negotiated and the correct pattern inserted, the factory is considered shut down. Bonus points are awarded and you are automatically moved on to the next, more hazardous factory. The action continues in this fashion until your supply of ships runs out.
'Durell seem to be slipping - Deep Strike was less than pleasing, and this is a bit iffy too. At first Sigma 7 is compelling, but once you've got the hang of all three levels it proves to be far too easy - so monotony sets in quickly. The gameplay may appeal to high score bandits but I doubt it will keep most gamesplayers happy for long. The graphics are fairly impressive, there's always a lot of colour on screen and the characters themselves have been nicety drawn. The front end is excellent, the game logo flicks up beautifully at every given opportunity, and there's a brilliant 48K tune.'
'I suppose that when you've released as many superb games as Durell have you're bound to get a few duff cookies. Sigma 7 is a great disappointment. The graphics are very solid but not very well drawn, and there's appalling colour clash on the first stage. The animation is simple and not very effective - the first stage suffers terribly from flickers and jerks. One good thing is the tune on the title screen. But that's about it. There's nothing in any of the stages that's fun to play. Sigma 7 is not worth the asking price on its own.'
'I really enjoyed this at first. It took me a while to understand the objective of the third screen, but once I had it sussed it became very, very easy. Within half an hour I was regularly amassing 20 or 25 lives every game... and losing them all a few levels later. Needless to say, I found this extremely frustrating, and therefore the addictive qualities I originally foresaw vanished in a puff of smoke. On its own, Sigma 7 isn't much of a game, but Durell's drop in price is a sensible move -and as it now seems that they're offering a ' buy one get one free' policy (and we're talking games like Thanatos and Fat Worm here, not yer usual freebie rubbish!!), Sigma 7 represents good value.'