Ever wanted to be a crazy inventor, building amazing contraptions to boil eggs or toss pancakes?

It's been a well-loved theme for centuries, culminating in those wonderful illustrations by Heath Robinson for the Professor Branestawm books. Now Software Farm, previously associated with hi-res ZX-81 games, has transferred the whole idea to the Spectrum.

Potty Professor isn't really a game at all, in the conventional sense. You are given six problems to solve, and a variety of objects to build a machine which will do the job. By way of example, the first problem is to flush a toilet, using a dog, cat, bucket, watering-can, one ton weight, see-saw, balloon, blowtorch and tongs.

A cursor selects objects and moves them around the screen. When you think you have a workable machine, you press a button to set it going and watch the results. If you are not successful the contraption falls apart.

Objects can be used two or three times in a machine, and some won't be needed at all - they are there to confuse you. You should experiment by seeing what small combinations of objects do to each other.

The animations are well-done within fairly crude cartoon limits. Outstanding is the steam engine used in the egg-frying problem, which puffs and shudders most convincingly. There are a few problems with the way some objects connect, graphically speaking, but that is inevitable.

It's a super idea for a program, marred only by the fact that once you have solved the six problems there is not much else you can do. Although the problems are extremely difficult, the program has a limited playing life. Mind you, you'll probably want to show the inventions to your friends anyway.

Had the game included an option to design your own machines, which would have given it unlimited playability, it might have achieved a higher star rating. As it is, Potty Professor is still well worth buying for its originality and sheer good humour. It's certainly a fine omen for future Software Farm productions.