I will argue to my grave that it would have been better to rebuild the game using the reach engine and physics, and keeping the old X Box game as a "Feature" rather then repackaging something I could get on X Box Live for 20 bucks
The blocky assets are STILL frustrating to this day with sniper kill shots and well place rockets detonating in the empty space between two trees. I am reminded how there was a gaddamned good reason the Needler has had to be revised in every single Halo game, and the AR had to have its clip cut in half to double the firepower per shot.
the HD graphics overlay positively ruins the atmosphere of 343 guilty spark, the Library, silent Cartographer, and Keyes, where the low lighting levels helped the derelict artifact feel (and in the case of the library made the zombie apocalypse run possible.)
Here is the thing, There are two examples of successful remakes that should be held up as blueprints for remaking. Mega Man Powered up and Mega Man Mavrick Hunter X. Halo CEA is following the Mavrick Hunter X example, copying the old game verbatim with a few extras to justify the price tag.
MM Powered up though added two new bosses, completely changed the maps and reworked the difficulty to be more forgiving in the right places (yellow Devil) and less forgiving in the right places (Ice Man and Fire Man). I would be much more satisfied had 343 manned up and took THAT route rather then lazily releasing the same game I have played for a decade.