Bug fixes and improvements :
- the annoying music now play for each level
- the game pause itself when unplugging the controller or tabbing out of the game
- fixed some geometry issues in some levels
- UI should now scale better with different resolutions like Ultra Wide Screen
- added Steam Cloud saves
- added 14 Steam achievements

There are still things I want to improve / add / polish, but those where the most important imho.
Enjoy!