Necronomicon
It’s late at night. You can’t write another word, the wife has left for bed and you should pack it all in and go to dreamland but you need a last fix on the computer. I recommend
Necronomicon
A neat little bit of madness by GamesofCthulhu
You can find the game here.
http://www.kongregate.com/games/GamesofCthulhu/the-necronomicon
It’s a little bit complicated but once you have the hang of it you’re hooked. While you work it out strange noises will emerge from the deep to keep you looking over your shoulder.