Ugh. Gameplay eludes me, still. The monsters are either too smart (they avoid line of fire unless they have no choice) or too dumb (if you have yourself set up with a single line of approach, you can kill the entire lot with no further trouble).
I may end up transplanting my proven ThiefRL stealth gameplay to this game; have it be some sort of interplanetary heist. Wouldn't be the worst thing.
In the meantime, I've done some level generation stuff. This is based on Loop subdivision with noise added: