Too short
Graphics 8: The graphics seem to be the same as halo 3 so it seems to be running of the same engine as halo 3, it has a little bit of nicer colors so id say that it is slightly better looking but still a bit outdated compared to how some of the current games look like, i give the graphics an 8.0
Sound 7.5: It is a good sounding game the grunts say some new funny stuff occasionally which is pretty cool, the soundtrack however is not as good as the soundtrack from halo 3.
Difficulty 5.0: Not very hard me and my friends died only a couple of times in the entire campaign on legendary, even though you don't have regenerative health like you do in halo 3 and have to pick up medpacks intead it is still easier which suprised me
Overall i think it is a good follow up to halo 3 (but not as good as halo 3) but i also think that it is more of an expansion then a full game and you can tell by how short the singleplayer is, although you get some extra hours out of the new firefight mode it is still not worth the full retail price especially considering that the multiplayer is actually taken from halo 3.