Despite being pretty much a Nintendo fanboy, I'm also one of the biggest Halo nerds around. I fell in love with it after playing a demo of the PC version, and then got Halo 2 as soon as I bought the original Xbox. I got Halo 3 as soon as I got a 360, and Halo: Reach when it came out. My mom asked me what I wanted for Christmas this year, and I mentioned nothing but Halo 4. I played the game yesterday to make sure the disc wasn't defective, and I'm very impressed.
For those who don't know, this is the first legitimate Halo game not developed by the original Bungie team. I remember when 989 studios took over the Twisted Metal franchise, and how badly it stunk with the third game they made. But 343 Industries is not the same, as they took what made Halo great, and evolved upon that.
I played just the first mission of the campaign, and I was very intrigued. I was impressed by the story where Master Chief is shipwrecked in space and is awaken from his slumber by a rogue group of Covenant forces who didn't recognized the truce initiated after the events of Halo 3. They are near a mysterious Forerunner (the group that created the Halo rings) planet, and I'm sure I haven't seen nothing yet.
I also played a few rounds of multiplayer, and I'm glad to see the variety of special skills and weapons return from Halo: Reach. Except with minor twists, but a good bit less focus. There are a lot of good new weapons, and I like the current maps so far. They're much simpler in design, and I felt Reach had too many hallways and rooms that weren't needed. The game is wrapped up until Santa's big day, but I can't wait to play it again.