A simple, but fun and charming game. You guys definitely have a nice vibe going on for your game, and I would love to see this fleshed out and on my twitter feed one day. There's definitely a lot of places you could go with this mechanic and the humor and art style you're building here, so please do keep it up.
For adding new modules though, I would just make sure to be thoughtful in your designs and don't be afraid to get weird with it. Try to break away from the stat number upgrade and add stuff that makes the players go "YOOO WTF!!!", then it'll be a real special game you guys got.
I really like the art style and the music as well. Overall, keep it up guys! Nice work!
Also I want to throw out there, I wouldn't mind helping you guys out if you'd have me. I think it would be a blast to work on a larger project with a team, but no pressure.