Was the game you were trying to think of solar Jet man or Jetpac.
Nope, it wasn't either of those, but thanks for the suggestions.
I thought it might contain Lunar in the title but doing a quick search didn't reveal anything similar. It definitely isn't anything like Lunar Landing or Lunar Rescue.
Did anyone else own a CPC at the time? When developers actually coded directly for the CPC range the quality of the games could turn out looking exceptional, and graphically beat the C64 easily. But sadly most were poor ports of Spectrum games and made the CPC look much less capable that it really was.
Obviously it did fall short of the C64 in terms of audio as the CPC audio chip was nearly the same as that found in the Acorn BBC range with three channels and a noise generator, outputting to three channels in mono, compared to the far superior C64 SID chip.