F1 - Debug Menu
If the settings file have LoadDebugMenu set to true, then the debug menu can be accessed. Here lots of nice stuff can be found. In order for most of the other shortcuts here to work, LoadDebugMenu must be set to true.

F2- Pause
This pauses and unpauses the game.

F3- Fast forward
This games the game run for times faster. Good for skipping sections.

F5 - Reload
This reloads the current map.

F7 - Spectator Mode
Changes to spectator mode, which allows you to fly freely. Constrols are. WASD, Shift, Space and Ctrl.

F8 - ScreenShot
This takes a screen shot and puts it in the same folder as the exe file. You can change ScreenShotExt in the settings file to change the format.

F10 - Quick Save
Saves a save-game.

F11 - Quick Load
Loads a save game.