Children of Mana is the latest Squenix addition to a long line of Mana RPG/adventure games that have moved into the Nintendo handheld world - this one being a game for the DS. And out of all the mana games I've played, it is by far the worst, and possibly one of the worst RPG games I've played. From story to game mechanics, this is almost a complete lemon, so if you dislike negative reviews, just skip this. I'll try and summarize the paragraphs so you can get my main points without having to read my entire tirade.
Complete lack of utilization for the DS hardware.
The first thing I noticed about the game is the complete lack of stylus play, and the poor utilization of the dual-screen system. There's all this fantastic hardware for DS, and most of the games I've played have used it to some good effect, but CoM almost completely ignores it, opting to use one screen for maps/status when in most cases, your maps and status aren't really needed. After the opening screen, the stylus is not used at all. In fact, I have to wonder why they even put that one touch-screen in there.
Complete lack of character story.
Even in the last GBA handheld installment of the series, the story had depth. Your characters had a history, and a reason why they met. And the supporting characters had some really touching material. In CoM, the village priestess is kidnapped, and all the village elders and warriors get together to discuss what must be done. Your character, who seems to have no real station in the village, voulenteers him/herself to go, and everyone is just like "bai. the potions shop is to your right on your way out of the village." Not even a "no, it's too dangerous!" or "let me teach you how to fight before you go." And that's only the first of many such oddities. Either the localization team has completely butchered and removed whatever insightful dialog existed, or it just never did.
Complete lack of story
Sort of ties in with my last point. At the end of each zone, you fight a boss monster, and someone comes out to tell you "good job" and give you the tiniest scrap of explanation and some artifact that allows you to access a new area of the game. You go back to the village, speak with the veteran, and he asks you to go scope out another crisis. Of the handful of zones I've been to, that's been the extent of it. Sidequests are available through a shop, but you never meet who you're helping, and the fun of discovering the sidequest is eliminated because they're just handed to you. So far (though I'm assuming this changes later), there are no towns to explore, and no benefits to talking to people.
Weak character development
And by character development, I mean level progression and the like. Most of your development happens through the aquisition of new weapons and armor, and the equipping of various gems you find. You can fuse gems together to create new gems with special powers. But that's pretty much it - no points to spend of any kind. All of your weapons and armor can be purchased from the shop, so questing for special weapons and armor is pointless. Furthermore, all wares have a level requirement, so apart from gems, there's no good way to max out a particular stat.
Shallow and frustrating gameplay elements
Your 8 espers exist, but you can only take one of them into a dungeon with you, as opposed to previous games, where you do work to find the mana, and then its unique powers are available to you through the rest of the game. You cannot access the weapons, armor, or gems you pick up while you're still in the dungeon, or swap out your esper, until you've reached a save point. Each dungeon has multiple levels, and if you leave or die, you have to start the dungeon over again (or simply restart your game from your save point if you reached one while in-dungeon). The new gameplay mechanics are not always explained in the best way, such that I had to actually look up how to use and switch my espers.
The only positives...
There are four weapons that allow you to complete some puzzle-aspects in the dungeon, and you have the ability to dual-wield so you don't have to keep switching weapons, which is nice. The graphics are cute - the whole game definitely looks just like a mana game, and there are even a few anime-style cutscenes. Your performance in each dungeon section is scored off how many monsters you kill, how many chests you find, and how fast you do it in - and from this, you can get special rewards. There's a multiplayer option, which is new and supposed to be pretty fun.
I was surprised to find this used so quickly, considering it only came out a short while ago, but now I see why. By itself, any one of these flaws wouldn't be enough to ruin the game, but this many annoyances and shortage of RP aspects together make it an almost worthless pursuit. It's fine for a dungeon crawl, but with so little rewards, why not just replay a more compelling dungeon crawl game? I recommend D2 for solo play, and Gauntlet, Zelda Four Swords, or FF Crystal Chronicles for really fantastic multi-player dungeoncrawl. And, if you're interested in how the Mana series is done well on a handheld, pick up Sword of Mana.