I loved it. It's definitely the best survivor game I've played in the Jam. I especially loved the art and animations of the different aliens.
The only complaint I can make is that the progression is a bit too slow. For a Jam sized game I want to be unlocking new content and characters almost every run, because I want to see everything you worked on.
Oh and the 'Story' option was off by default so I almost missed the thrilling intro cutscene.
P.S. You should make a web version if you can. It's the main reason you have so few ratings/comments on such a well made game.