Version v0.3 is now here!

Changelog:
-More buttons can now be rebound
-Mouse x/y can now be inverted
-New graphics option: low/high quality lighting
-Graphical UI improvements

Gameplay:
-Weapon upgrade menu! Much better than doing it from the inventory.
-Five difficulty levels: Very easy, Easy, Medium, Hard, Very hard
-Help screen, accessible from the main menu. It tries to explain some things

As always, all comments and feedback is welcome!