When I open the game, the usual loading screen will appear. Nothing happens after that -- not after 5 seconds like usual, not 5 minutes later. Ctrl + Alt + Del appears to do nothing, but it seems like the Windows Task Manager does open up. Instead of the Legend of Grimrock cursor, I see the Windows cursor where the task manager would be. Hitting the Windows key on my keyboard has the same effect!
Windows has no new updates. Steam, no new updates. Grimrock and Nvidia drivers, no updates. The game worked fine just yesterday.
Hopefully there is a better solution than having to delete the game content and reinstall! Thanks in advance.
Edit: Welp! It works now. Guess I just needed to give the loading screen a little bit more time. The game opens without problems now.