Yet another gang of inter-galactic master criminals has planted a bomb in a nuclear power station; this time the criminals are General Ironside and his Metal Army and the power station is in Slough. An attempt at being witty there, I think; I suppose they're half-way there!
Anyway, what it all boils down to is a pretty big (from what I've been able to explore), very hard platform/maze/shoot-'em-up in the best budget tradition. Though there are scores of games like this around, very few do it better than Metal Army (Koo-er! eh?). This will keep you occupied for quite some time, so you won't have to resort to looking for smutty double entendres in YS reviews for a while.