What the back of a game's box won't tell you:
2-Player! (VS mode only, unlockable after about 16 hours into single-player mode)
Online Play! (No chat though, so you should probably play single player against the AI for a better balanced game anyways.)
Over 60 Hours of (Very Repetitive) Gameplay!
This came up when a game designer colleague mentioned something about the relationship between game developers and game advertisers. He said that if you let game advertisers get involved too early in a game's development, that they will start asking you to add features so that they can put them on the box.