For those who have played Metroid Prime 3: Corruption, is it like Metroid Prime?

I really liked the original Metroid Prime and recently decided I wanted the Wii sequel, Metroid Prime 3: Corruption. However, after reading one lukewarm review, I've suddenly had doubts about it. Although the overall critic score is quite high (around 9/10), I wanted to ask this: Is it like the original (and the first sequel)? I know that shooting games can be fun (look at Halo), but I want a game that also involves exploration and puzzles. The first two Metroid Prime games struck a great balance between solving puzzles, exploring new frontier, and fighting. I've heard that MP3 is "more combat-oriented", but what about the level design? Please tell me about the things that I look for in a Metroid title - don't say "It's like Halo and a lot of fun". Thanks.