The concept behind Planet Monsters is simple. You travel from board to board trying to eliminate the three opposing main monsters while avoiding local monsters from that world. I forget when I'm away from the GBA for a while just how good games can look on that little screen. The main monsters remind me of small versions of that orange monster from the Bugs Bunny cartoons. The rest are takes off of normal wildlife like elephants and crocodiles. The sprites are well drawn, colorful, and full of animation. The music changes from stage to stage, but there isn't anything that catchy, so you won't be missing much if you have to play with the volume turned down.

The stages are set up very much like Bomberman. They are maze-like with power ups scattered throughout the board. The major difference being that the blocks that make up the walls of the maze can be kicked out of place, and they slide until they hit another wall, enemy, or fly off the stage. This is the basis for gameplay. In order to eradicate the opposing monsters, you must smash them with a sliding block. Walking through an enemy does not hurt you, but you do lose a life if you mistakenly run into one of the native monsters to the world.

To make things more interesting, you can pick up items around the board that will help you be the last monster standing. There are bubble cannons that freeze the opponent so you can kick them off the stage. There are clocks that freeze all but yourself in place so you can do a little damage with no counteraction. There are even springs for you feet that allow you to jump over walls or gaps in the ground. The cool thing is you can have more than one type of item in your inventory at once, and you cycle through to what you need with the shoulder buttons.

The stages become larger and more complex the farther you get in a single world. Once you completed all the sub stages, you are treated with a boss fight. The bosses are killed in the same way, but they take a significant amount of punishment before they go down. The boss fights almost feel more like a top down shooter than anything else. My biggest gripe with the game and one that really does hurt the overall effort is also related to these stages. They get big, much bigger than any Bomberman board that fits on a single screen. In doing so, you can only see a portion of the game board at any given time. Your only aid is a small radar in the bottom right hand corner which shows the relative location of the opposing monster (but not the native baddies). It's not even a scaled down version of the map. It's just a four-quadrant grid with four circles on it, and it's not much help. You'll be too worried about a monster walking into you to be able to take your eyes off the action and analyze the radar.

The tightened view does turn the game into more of a twitch affair then I think was intended, but it doesn't wreck the game. Maybe they wanted to show off their keen monster designs and animation that would have been lost on smaller sprites and a smaller game board. Planet Monsters is still a classic candidate for portable gaming. If you like the old Bomberman series, and especially if you have friends with GBAs for four-player combat, this will provide you with some small screen enjoyment.