Really eerie concept delivered with a strong mood, that reminded me a lot of the recent Spanish film The Platform. The restricted mouse movement made me feel super claustrophobic which really added to it all!
Like the others below the menu thing was slightly annoying, as I wanted to jump right back in after I lost the first few times. I also thought it could be good to freeze the mouse movement while reading the papers. But, hey, these are minor in the grand scheme of things.
Really great idea with a very strong affect!