Captive (Mindscape 1990, Antony Crowther) Amiga/ST/PC
Cappo, is basically a futuristic Dungeon Master clone, or dungeon crawler if you like. It had lots of neat technical touches, like buying 'apps' for your squad of droids, interchangeable body parts, tons of enemies, and a practically infinite game world. It's my all time favorite game, I spent whole summers playing it. It was made back when games could be created by 1 person, even though it's massive, it uses a clever level generation technique to squeeze it all into a 512k computer.
http://www.youtube.com/watch?v=qI3194aVsHY&feature=related
The creator has said that he doesn't want anyone remaking or doing anything with Captive... I can always hope that an iOS version appears. There is a cool looking 3D version of Dungeon Master in the works, I guess I should give that a try.