An overrated shitty game, very much like a regular 1st person shooter. Not revolutionary whatsoever, bad FPS, sucky graphics, kind of fun gameplay, but not really. Multi-player adds a little fun to it. Half-Life 2 owns Halo 2. Just to name a few things, HL2 is revolutionary, completely built-from-scratch engine, best physics engine around, best graphics of any game right now, unbelievable AI, and contains Counter-Strike: Source, which is 10x better than Halo 2. Received many Game of the Year awards, and a 9.8 on the game reviews - highest rating ever given to a computer game.
Halo 2 sucks big time, and I can argue about it so much and win.