What kind of poll is that?
First of all, there is no way in hell it takes more than 11 hours to complete Halo, unless you're AFK for 5 hours.
Secondly, FPS games are generally extremely short, so tagging that as a 26-30 hour game is complete bollocks.
Thirdly, there is no 60+ hour option, which would include games such as long RPG's ( Oblivion, MMORPG's ).
Furthermore, the length of a game depends on the type of the game. I wouldn't want to have a 10 hour version of Ikaruga, but I do like long RPG's.