The Doors to exasperation

Contraption Zack For IBM compatibles AT FIRST glance, this offering from The Software Toolworks looks uninspiring. The aim of the game is to help Zack, a new factory employee, find his way through the plant and start various machines and gizmos.

However, it turns out to be far more complicated, requiring much thought and ingenuity. Unlike most games, Zack does not need fast reflexes and a desire for mayhem and blood flowing in gutters. Instead, the ability to think in three dimensions is required - as is a fair amount of patience while you stare at a seemingly insurmountable problem, knowing full well the solution is not as difficult as you imagine.

Essentially, electro-mechanical technician Zack is the ''new guy'' at Gadgetco, Inc. The rotters he works with have stolen or lost his tools, and the boss is screaming at him to get the plant working . . . NOW! You have to find the tools in the maze that is the factory, and use them to fix things, overcome obstacles and clear paths. Zack is propelled through the factory using the cursor or numeric keyboard keys. The various parts of the plant are displayed one by one as three-dimensional cross-sections, with arrows indicating the inter-linking corridors. The game often requires the retracing of your steps after discovering a contraption which will help overcome an obstacle which stymied you previously.

The most helpful items are buttons set into the floor, which cause spikes to recess and paths to clear. Of course, not all buttons are helpful, and depressing one too many or the wrong one in sequence can put you in an even bigger pickle and force you togo back to the start of that level to try again.

The other most common aids are the switches, which have to be operated in the right order to get the required result. They often have to be operated in conjunction with screws or nuts and bolts, which in turn have to be turned with the tools you do not have - and which, irritatingly, are often on the other side of the obstacle you are trying to surmount.

Irritating, yes, but satisfying when you find the solution, which is usually staring you in the face. Staring back is useful, especially when faced with The Doors. These were the bane of my life: a series of successive doors opening and closing at randomintervals, at the far end of which is an almost complete set of tools.