I played "regular" 12 hours matches of Starcraft (custom maps) with a group of friends of mine back in the day...
We played 3 days straight, no sleep, downed 2 cans of coffee and almost went to the hospital after our parents found out, rofl. Just keep the food coming and tell your folks you were having time for sleeping, hahaha.
Ah, the good ol' days...
I'd say the feat here was GTA IV being played more than 15 minutes straight. THAT's a feat of strenght.
Cheers!