'GET SHREKT! - GOAT SIMULATOR'

Goat Simulator is a game where you play as a goat. The obvious way to modify this winning formula is to change the goat to Shrek. 'Get Shrekt! - Goat Simulator' is a Youtube video charting the resultant gameplay: watch Shrek's bizarre, ragdoll body crash into things and soar majestically up towards the heavens. It's like Saint's Row's Insurance Fraud minigame, except even stranger. Add a DnB background score with Shrek repeatedly asking you what you're doing in his swamp, and you have a true internet treasure.
Also you are now insane.