I've read a lot of reviews where people complain about how this game is the same as the first one just with a few extras. Isn't that all a sequel is? Differences between Halo: Combat evolved and Halo 2? Slightly better graphics and a couple new guns. You want another example? Look at all the sports games that are put out year after year. What are the differences between madden NFL 9 and 10? Different names on the jerseys and maybe a couple of different stadiums.
I played the first game at a friends house. I wasn't a big fan. Then when I saw this one was coming out, I thought I would try it. I played for about and hour and sent it back. It is exactly the same as the first one. If you liked the first one then you will love this, but I didn't.