The new build contains "Spudge's Water Park" (a semi-dark location), and the default number of pixel lights has been boosted to 24 (which shouldn't affect framerate) to keep the lights in portions of Spudge's from flickering, but existing players (who already have a user settings file saved) may need to change it manually by going to Settings and adjusting the pixel lights up to around 24. The previous default was 16.
Also, some bugs were fixed including a glitch which prevented some of the user settings from being applied at startup.
Here are some screenshots of the new location:
