Awesome game, completely changed from the other MegaMan Zero titles. The Game play has been kinda upgraded, instead of using elemental chips or forms used in charging, you got 7 new people who control different elements and powers that you can play as. As long as you played MegaMan Zero 3 or 4, you should be able to understand this one.
What was great about this game was the character change mode where you could switch between 6 different M.E.G.A. men who are from the previous installments and they all have their own powers and abilities, like Model HX being able to hover and boost long distances or how Model LX can swim in the water rather than sink and it has a more open environment to explore with more people around.
Also! The game is !Extremely! difficult at times since they got rid of the cyber-elves so you better be skilled at playing this game or have a high tolerance for anger! Playing as the boy is a little easier than the girl's so it shouldn't be so hard if you start as him.
I highly doubt this will be the only Mega Man ZX on the DS, but that doesn't mean you shouldn't try it out. It's a really good game with a good plot and a lot of side quests that help.
If you are a fan of the Megaman Zero series, then you will love this game as much as I did and I rather enjoyed the game. For those of you who are new to the series and want to get the full benefit of the game, then I suggest playing all the previous games because if you don't the story will get a little confusing. Other then that, it's just another cool Megaman, side scrolling hack-and-shoot game