The Good - Great Halo world feel. Best CGI I've seen in a game, absolutely stunning. Smooth learning curve. Most fun I've had on Xbox Live in a fair while.
The Bad - Campaign's a tad short and leaves you wanting more. Multiplayer points/ranking system rather strange. Can get repetitive. Population cap could have been slightly higher.
The story is set before the events of Halo 1, which is a nice flipside of the timeline FPS Halo games follow. This means that there are far more Spartans this time round. It's also pretty cool for anyone who has read some of the Halo books as there are tons of plot line references that coincide to make a pretty solid story, trouble is it's not a long one. CGI is one of the best parts of playing the campaign mode because every so often you are treated to a superb cut scene which makes finishing that mission that little bit more rewarding. There's about 12 hours to it, my advice is you should play it on heroic or you'll breeze through it.
RTS's have never faired too well on the console, I never usually go near them but this one has pulled it off very well. It's traded detail for simplicity and it's been done very well. You'll find yourself starting to do things almost automatically after a short time and I experienced zero frustration whilst moving mass units or micro managing others. The tutorials provided are a good way to set you off, playing a few heroic skirmishes against the CPU will also teach you a few things. Multiplayer IMO is the best part of the game play. Nothing beats you and two friends totally rampaging through 8 enemy bases with a mass army, it's pretty fun.
As said before the CGI in this game is truly wonderful and it's a shame that this makes the in game graphics look a tad dated, even though they are still pretty good. Don't zoom in too much on flying units either because they look awful close up. Overall though the graphics are fine, nothing wrong with them, it's just the game play visuals have got fierce competition with the CGI visuals. The Frame rate also holds pretty well, the only dips I experienced were in 3V3 with about 300 models on screen, so it's pretty impressive.
It's Halo VS RTS themed music, and it's epic. Also considering the music composer isn't Marty O' Donell (Bungie's soundtrack man) the feel of the tracks is dead on.
Great game and worth a buy, especially if you're a Halo fan. If you're not it's still worth a pick up because it's a solid game that has been made very well. Just don't expect too much storyline from it.