That turned out really nice! Love the low budget too - I'm always down with cheap but awesome builds. 
Only thing I'd want to try would be to hook a fogger into it for short, random bursts so it looks like it's got a cryogenic converter leak and the alien might defrost...
(and the glycol might look cool condensing on the window area) but if you're showcasing it inside, that could get messy! But there's space to hide the fogger undernieth, and if you had a wireless remote (I do on one of mine) it would be fun to have a few hoses lose and maybe one directed into the alien chamber so you could hit it and use it as a jump scare too.
Only thing I'd want to try would be to hook a fogger into it for short, random bursts so it looks like it's got a cryogenic converter leak and the alien might defrost...
(and the glycol might look cool condensing on the window area) but if you're showcasing it inside, that could get messy! But there's space to hide the fogger undernieth, and if you had a wireless remote (I do on one of mine) it would be fun to have a few hoses lose and maybe one directed into the alien chamber so you could hit it and use it as a jump scare too.