I always think that playability is the most important virtue of any game. The sound may be poor and the graphics crude but if it's playable, I'll keep coming back for more. Also, with a few notable exceptions such as Elite, simple ideas often make the best games. Breakthrough from Audiogenic is one game that can be described in this way.

Although the title makes it sound like another Breakout bat and ball clone, Breakthrough is totally different. It is basically a 100 screen platform game in which you are a little wizard. Navigate your way around each screen avoiding the fireballs, vampire bats and various other nasties, collect a key and make your way to a door. It's simple - or is it?

The controls are certainly very easy to use: Left, right, jump and create/destroy a block. It's this last feature that holds the key to the whole game. By destroying existing blocks and creating new ones you can change the shape of the screen by making doorways and staircases in which to gain access to unreachable nooks and crannies.

Certain types of block can't be destroyed and these are invariably positioned awkwardly just to make things difficult. When used in conjunction with fireballs and the other nasties they can produce some very tricky screens. However, there are certain compensations: Some blocks contain hidden goodies that can give you bonus points, extra lives, or half the speed of the countdown timer. Very useful.

The 100 screens are not linked, as in an arcade adventure. They are separate but in order of difficulty, and a useful screen skipping facility is provided so you don't have to start at the beginning each time. Each five screens you are given a new password which can be used to skip screens you have already mastered.

This is certainly an engrossing game, and is extremely addictive because of its simplicity. The graphics are rather small compared to those used in many other games on the market these days, and there is a strip of garbage across the top of the screen, but don't let that put you off - it's a great game.

There isn't any sound to speak of, just the odd effect here and there - and it runs fairly slowly, but this isn't a problem. In fact it positively helps, as I found it unplayable with my Slogger Turbo Driver switched on.

Breakthrough is not too hard and strikes me as being an effective way to encourage children to think logically - there are certainly enough puzzles to ponder. If you are after something a little out of the ordinary, this could be right up your street.

This is great for puzzle fanatics. The graphics are good and the screens are well thought out. The first presented no problems and took all of five minutes, but they get progressively more difficult. It's nice to play a non-violent game for a change. I think I'll just have one more go and see if I can crack screen 11.

Martin Reed