There's a cheat code present in-game.
Type zefcklzefckl while in-game and you will hear a confirmation sound.
Then you can press the [END] key to show the debug menu (where you can spawn ammo, activate god mode, teleport to any zone etc..). There's also F11 for the trophies menu.

If you have already finished the game or if you're stuck somewhere, that can be useful.
Enjoy the unlimited ammo, god mode, teleport and everything.