I'm pretty sure that what made Halo fun was playing with your friends, both without lag and with more than one other. This game only has 2 player online co-op, something alien to the Halo franchise - you would think a company devoted to making Halo fans happy should at least have given the game 4 player online co-op, which had not lag issues (WHICH IT DOES).
You would also think that the graphics would be on-par with the most recent Halo Game, Halo: Reach. The graphics are of a very low standard compared to this and don't even stand up to the graphics of Halo 3, which was released in 2007.
Overall a huge disappointment for the Halo franchise and 343 Industries.
I advise getting the original Halo: combat Evolved on PC instead, where you can actually play with your friends together.