Thanks a lot for taking the time to play the game and give feedback! I'm happy to hear that you're enjoying the game. Having the different subsystems interact in fun ways was definitely something we aimed for in the design.
As for the UI, you're entirely right! We use a lot of generic assets for buttons, windows etc and standard fonts for most of the text. I'm the one who does most of the development and I'm not very artistically inclined, so I'm afraid there's no avoiding the programmer art aesthetic :)
Apart from the appearance, was there anything in the UI that you found confusing or hard to use?