If you tried the new patch that just released a few days ago and encountered some bugs, you are not alone. I seen some bugs including some errors that appeared on some bosses and chests that were inaccessible. So here is the thread on the official forums that bring to light some issues.

http://community.playstarbound.com/index.php?threads/bugs-for-risk-of-rain-v1-1-1.77890/

I have encountered two bugs where I was unable to continue and had to kill myself, so ever since I found out that it wasn't just me I decided not to play it until it's fixed in a later update. I'm not really angry that this happened as I did beat the game once and unlocked almost all the characters I just wanted to let people on GOG know. Besides I was so addicted to it that it was the only game I was playing for over a week so I just got to play other things.

Anyway hope that they can fix this soon because this is a really good game that I want to do well and it being somewhat broken doesn't really help it much.