Now this is a maze for the expert. Indeed, there are eight separate mazes of increasing difficulty in Cobus Maze, ending up with invisible keys to collect and invisible mines to avoid in the nearly impossible final game. The last four mazes require a separate LOAD for each, while the first four all operate on one LOAD, which gives an idea of their comparative complexity.

Cobus Maze begins with a fairly straightforward maze, and you are placed at the centre top. Distributed about the maze are cross-shaped mines, and the deadly Cobus is searching for you. If you're cornered by Cobus, you have five Zogs to zap him into hyperspace, but if he gets his zap in first, you've lost.

If you avoid all these perils, which is by no means easy, you progress to the next, more difficult game, and so on.

One side of the cassette is for joystick, the other for keyboard control.

Very rudimentary graphics and sluggish response to either keyboard control or joystick, where you either don't move at all and then suddenly jump right into a mine or monster, add up to a game that promises to be boring and hard to play.

On the other hand, as you get into it and master its idiosyncrasies, the possibility of becoming a maze-master can get you hooked, and I can envisage nationwide post-maze hangovers as people play all night and progress.

The first four mazes are fairly obvious, and if you lose all your lives the first few times it's a help that it always loads the same pattern of walls and passages to wander through.

In maze 5 you have to collect a key to get out and in maze 6 you need four keys - in the correct order. In maze 7 the four keys are invisible so you can't see which key fits what door, and in maze 8 there are invisible mines to avoid as well as invisible keys to collect.

I found the keyboard controls marginally easier to use than the joystick version, but I'd have been happier if there had been something obvious like U-D-L-R - or even W-Z-A-S - which at least makes a logical pattern on the keyboard.

For masochists only, but for them essential.