UI
-controller support (steam, ps4, xbox360) (xbox-one might work, untested). Make sure you only have one controller plugged in at once, and if it doesn't work at first, try relaunching the game.
-in-game options:
-controller settings
-sound settings
-bindings settings
-graphics settings
-clearer mini-map and icons for all in-game UI
-brief loading screen for loading levels
Mechanics
-smooth movement
-more responsive shooting
-aim dow sight: look speed proportional to zoom
-motion blur used when hit and on game end
-buy / reload same button (hold vs tap)
-fixed glitch which caused you not to jump sometimes
Sounds added
-crawler jump
-out of ammo
-different lose music
-purchase sound used more places
-antidote sound and particle effect
Translation
36 languages, see game description
Game
-start with pistol
-1.5 times more health for polygon hero (you're welcome)
MUCH better tutorial (the first one sucked)
-fixed highscore posting twice glitch
ENJOY
Also, I do read reviews and the discussion boards, so keep letting me know what you like/hate/whatever.