I had a game on my ST which was basically a shoot 'em up (viewed from top) but it had a unique feature: you had to hover over buildings to collect different elements or gases or something and only then you could finish a level. I'm quite sure it was a pre-90s game but I could be wrong. Definitely earlier than 1994 or so, though.
I had the game on a PD disk so it could be shareware. Then again I had Ammotrak on one of those disks, so it could be just unintentional piracy. ;)