This was absolutely brilliant. If I recall correctly, there were four or five different levels which you could chose from at the start of the game. Absolutely rock hard though - your timing had to be spot on. I got about halfway through most of the levels, but sadly didn't finish a single one!
If my fading memory is correct, this game was written for a competition run by ST Format following on from a series of assembler tutorials written by Bullfrog.
This was on the cover of STF 30, the second ST magazine we ever bought, which we got just before the computer (an Xmas present), so there's a definite nostalgia value. Kind of a Rick Dangerous clone, and very slick for PD, I still think of it as one of my favourites...