This game is a blast. A real quality remake of the original in my opinion. For those who haven't had the pleasure of experiencing the original, don't worry. The original game is included as an unlockable at the end of the game. All sorts of improvements are in the game. New moves, wonderful, vibrant graphics, and a whole new chapter after you defeat Mother Brain. I won't give away too much, but you're going to be able to see more of Samus then you have in any other game. The new chapter also helps to bridge together the events of Prime.
There are also statues that help guide you through the game, because its easy to ghet lost. Believe me, try the original game after you beat Zero Mission. It's nearly unplayable compared to Zero Mission.
After playing this game, I really must say this is a must play for any Metroid Fan, and a good pickup for anyone who has never experienced the magic, that is Metroid.