I still need to come up with enemies for this level! Any suggestions?
For me it looks like Mars'ish or kinda Desert'ish... In both cases, "Flying Saucers" is an option (on Mars or in the Desert, Area 51, hehe) ;-). On the ground you could have threelegged Spiders, which also fits to 50/60s Horror/SciFi Films and would be a nice reference to "It came from the Desert". Also, if it's on Earth/Desert, big wolves or camels, packet with rocketlaunchers or railguns, would fit. Or, if it's on Mars, why not green littl' men, with laserguns? ;-D