I recently got through playing this game, and wanted to write up a review explaining how I feel.
So I've played the Mario and Luigi games that came before this one, and loved both. I even went back and replayed superstar saga after I finished it, but unfortunately I didn't feel the same about this one. It was as if something was missing, or perhaps something was there that shouldn't have been.
Story: The story was actually pretty good. You start off in a meeting at Peaches castle in order to try and find a cure for a mysterious disease that has struck the mushroom kingdom .The Blorbs. It's making all of the Toads bloat up like party balloons and nobody knows how to get rid of it. A strange turn of events takes place in which Bowser is tricked into eating a strange mushroom which makes him inhale everybody at the meeting. Once inside Bowser it's up to you to find everybody else and help Bowser in his quest along the way.
The comedy was still there for me too. If you liked the charm and wit of the first two games I don't think you'll be disappointed.
Gameplay: This is where the game lost me. It's basically the same as the last two. Nothing really that groundbreaking as far as the combat goes, and even that's fine with me. My real irk with the gameplay is Bowser. Sure it sounds awesome at first. "Yay! I get to play as Bowser" I thought to myself with child-like enthusiasm, but halfway through the game my thoughts had drastically changed to "Why the hell am I still playing as Bowser?" It's just not the same. I thought I wanted what the game was advertising, but I was wrong. I have to admit there was an hour or so towards the end of the game in which I was having a blast, but it was only because I was playing as Mario and Luigi, but that was taken from me almost as soon as I started to have fun.
It wasn't all bad though. Some of the new special moves were pretty entertaining. Especially the one where you fed a bunch of food to Luigi and threw him at your enemies.
Graphics: The graphics are about the same as we've come to expect from the DS. Nothing really spectacular going on. It looks pretty much the same as Partners in Time did. The lack in a variety of enemies was fairly disappointing to me though. Most of the time I felt as if I was just fighting the same thing over and over again, and I don't remember feeling like that in the first two games. The environments inside Bowser get a bit stale too. They don't really change much. However in the mushroom kingdom you get to see some different places and a few of them are pretty cool. I particularly liked Bowser's castle.
Music and Sound Effects: The sound effects were pretty good, and the music helped keep a delightful feel around everything that was going on. The gloomy parts in the game sounded gloomy, and the happy times felt happy. I don't really have that much to say on the subject other than that. Nothing really wow'd me, but nothing left me feeling disappointed either.
Final Judgment: All of the elements of another great Mario and Luigi RPG seemed to be there, but the gameplay hindered it way too much for me. I'm not saying that it's a horrible game, but it didn't pull me in like the other ones did. Towards the end of the game it felt like a chore, but if you're a fan of the series at least give it a shot. It's not the game for me, but it might be for you.