Amnesia freezes on main menu, crashes.

[plutomaniac]

It's strange that it happens when moving the mouse and only then. Can you try another mouse? Otherwise, I will have to stick to some sort of software interference/incompatibility. Since you got the game from FG's store you have access to the Linux and Mac OS X versions as well so if you want to and can, sure, give it a try. My best guess for Windows would be software interference as I said.