Planted firmly in the difficulty level of "child," Pokemon Trozei won't become the next great item in puzzle gaming. Its absurdly low difficulty in the endurance mode is inexcusable, even for a game aimed at the younger set. Versus, confusing co-op, and brief initial story mode don't help matters. The only addictive aspect is, of course, collecting the Pokemon.
It's hard to find reasoning for the existence of Trozei when Tetris DS and Meteos are available too. Trozei's simplistic chain/combo system is its downfall, allowing for screen-clearing explosions by barely moving the Pokemon to line them up in rows of four. Once lined up and four disappear, any three combined Pokemon go, and then finally two. After beating the story mode, this changes so that chains can't start until you have five Pokemon lined up, then four, and so on.
Unlike the countless other games of this type, you need to move an entire line of Pokemon, not just the one you're looking to eliminate from the field. This does change things up slightly, though not enough to completely avoid the comparison to other game that this directly mimics. In all actuality, with the combo system as it is, moving an entire line ends up making things easier. Pokemon line up in places you didn't even see beforehand while you continue to clear the monsters you were aiming for.
All of this action happens on the bottom screen. The field actually takes both screens, and it's frustrating that the player can't line up combos on the top screen. You could fill the entire top screen with a single type of Pokemon and have nothing happen. Given that's the area where the game can end, it's rather inexcusable not to offer some way to create chains above the touch screen. Too many concessions are made on the bottom screen (moving Pokemon up briefly to create a chain, pushing them to the other side of the screen, etc.) while the upper playfield sits there.