There really isn't too much to say. It is a great remake of the original game. One really neat feature is being able to see switch between the original game and the HD version while you play.
One of the downsides is that it doesn't have all of the multiplayer maps of the original. It is a good rent, but not likely a buy since you've probably already played this a ton and the multiplayer community is really small.
Halo: Combat Evolved was the first game I ever really got into. As a fan of the Halo series I think 343 Industries did an excellent job recreating one of the best games of all time. The ability to play it in old school or new school mode by just a click of a button is amazing. The game is completely the same with no change in performance or feel. Its not so much a remake as it is just an updated reissue. Old players of the original will still enjoy the ability to "backpack reload," as well as other button mashing/glitchs that made the original so fun. The idea to add skulls and terminals to the story is great. It gives old players that played the original a chance to explore even more into the Halo world and fall in love with this amazing game all over again. Great job 343. My only complaint is WHY NO MULTIPLAYER?? Halo 1 on Xbox Live would be phenomenal.
It's halo, it's on xbox 360, it's as awesome as it ever can be. You can even change back to old style graphics at-will. What's not to love??? Even finding the skulls/terms was fun. It was enjoyable reliving it all over again!