So i'm messing around with the F-keys trying to find a save option of some kind with no luck at all.
When i hit F11 it went to windowed mode which i didnt want so i hit F11 again.
Now i cant switch between weapons, reload, shoot or do anything other than jump and move, also if i pick up another weapon my current weapon disappears and the new weapon does not appear at all.

Other than that i'm loving this game so far.


EDIT: Turns out that F4 was the culprit

Those Features on the F-Keys are really strange, to me they look like some sort of development / Debugging Keys. It makes no sense that the End-User should be able to enable a Wireframe mode.