What games are you talking about on there? If you say all the Nintendo 1st party games are almost guaranteed, remove Mario/Sonic b/c it's Sega but still Mario, and the 2 Resident Evil games and Guitar Hero which are no-brainer sellers, it leaves you with like 4 games.
Carnival Games, Red Steel, Rayman x2, and Lego Star Wars.
Carnival Games is random, and has been covered above.
Red Stell was the only real shooter, and early adopters wanted to try a shooter on the console. Rayman was early mini game - sequel sells on name alone. Lego Star Wars has sold every platform, so why not here?
And then you have the Sims, which has sold forever too.
I don't see what's so random about the million sellers here.
Can't we all just get along and play our games in peace?
