This is a bzflag map. You must change the extension to .bzw before this works.

BZFlag forever!

I didn't add alien buildings, my apologies, but you can if you wish. The foundation is a box, which sometimes causes not all of it to render and let in the grass below. You could maybe do something with it if you're ready to cringe at the horribleness of my coding (although in the bzw format it won't let you run the world if there's anything wrong.)

Have fun!