I got this free with my ST! Yay! Then I traded it for Carrier Command with a younger kid who didn't understand it and preferred this and Zynaps which was also on the disk.. Personally I thought it was a fair enough trade...
Similar to Goldrunner, and also Defender (you had to rescue scientists, and could go both directions). It regularly kicked my ass when I was little though.
Yup, very hard but also very beautiful. I managed to reach about level 8, and it was a really big pile of work. To be honest, I enjoyed goldrunner more - even when the graphix here are far better (Oh and the scccrolling).