Awesome game, very ambitions! It's almost like GTA for aliens. The UI and menu system work great, good font choice! The music is good, I like how it auto pauses when focus is lost.
All the work you put into building the world feels great. Theres a ton of detail here like the town area is incredible. The light and shadows hooked up to the ufo looks great. Id like more indication of where to go, maybe some kind of radar. Most of the time it runs pretty well but sometimes it has some very severe framerate issues like pausing for up to a second. I think you should focus on investigating the performance issues before you add more stuff, but theres a ton of potential here to build out the game, great work!