They raised a buttload of money and added some background animated art, some more ships, UI tweaks but I don't understand where all the money went (unless it went to Steam and servers for distribution.
PA just posted an article that goes into some detail on that:
PA Article Basically:
“With the additional funds we were able to greatly expand the sound and music design, hire a writer to flesh out the aliens and atmosphere, and run a very successful beta.”
Ben Prunty, the game’s composer and sound designer, was able to quit his job in order to devote more time to the game. The game’s soundtrack is now on sale via Bandcamp.
The music in this is exceptional. For some reason I never get tired of hearing it but the first time I played the game I just figured, meh, it's ok. Then after 30 hours I realized how much I was enjoying it. Sounds are also awesome. It's a fantastic well rounded product in my opinion.
I'd love for them to add crew member sound effects. Like screams of FIRE!! HULL BREACH! WEAPONS ARE OUT! Walter just got smashed by a rock monster!