Whereas Topologika's Hamil is set in a fantasy world that has everything from a Tyrannosaurus Rex to a bicycle wheel, their Countdown To Doom is pure space science fiction. It was originally written by Peter Kilworth for the BBC Micro and is a true classic in the adventure gaming world. It is text only and only available for the CPC on disc.

Peter Kilworth is the author of How To Write Adventure Games, a must for anyone considering writing his own operating system from square one. It is aimed specifically at the BBC Micro but the ideas presented are applicable to other machines.

Countdown To Doom places you in a spaceship that has just crashed on the planet Doom - shot down by the automatic planetary defence system. The atmosphere is highly corrosive and if you are unable to repair your ship rapidly you are done for.

Fortunately you are able to find out what spare parts are needed lit tells you in the blurb), so off you go in search of something to do the job. Treasures are also found, and will make you rich - if you survive.

The program is apparently written using a similar operating system to Kingdom Of Hamil, so once again we have no EXAMINE and certainly nothing as modern as RAMSAVE. As nasty things can happen round every corner, it is wise to SAVE often.

Help is on tap if you are stuck in exactly the same manner as with Hamil. No specific command instructions are given, but an adventure primer is included to help newcomers to adventures.

Countdown To Doom is full of ingenious puzzles and with its reduced price of £19.95 is well worth having, even if it does take you a little while to get used to a system that has now been superseded by those introduced by Level 9 and Magnetic Scrolls.