Why shouldn't it be? It's based on Halo, it tells a seperate part of the story. It's just an alternate genre that covers the requirements of the 'Halo' theme pretty well, with the units, their upgrades and pretty much all the in-game stuff. The thing I don't like is how lazy the Base system seems to be. I can't stand strategy games where you only get to build on a certain plot, or around a certain area. I like to expand and build my shit all over.
And also, there's a few flaws with the maps, as they pretty much all have glitch spots, even in campaign I've found a good few.
Combat Evolved is greater than Halo 3?
:/