Since I haven't played an extensive amount of the 1-player mode, but I have played the multiplayer mode. In multiplayer, you can either play on foot, use the Landmaster Tank, or the Arwing. Even though it isn't too deep, it's one hell of a time. There are about 10 different guns you can use while on foot. You start off with one with infinite ammo, but that is sufficiant to defeat enemies. There are machine guns, and rocket launchers.
In an Arwing, you have your basic lasers that can be chraged to do more damage. Also, you can find bombs around the course. The Landmaster Tank can use its basic rockets attack, and charge it to do more damage. It can even float to compete against Arwings.
In many games, vehicles give someone an unfair advantage. In this game, it's all balanced almost perfectly. It's great!
There are about 8 stages to start out with, but you can unlock about 10 more. You can unlock stages, new weapons, characters, new mulitplayer modes by just player a certain number of multiplayer matches. Kind of reminds me of Super Smash Bros. Melee. It's only a pain that you have to play 260 multiplayer matches to unlock the last thing.
This game is a great multiplayer game that is a load of fun to play, and very easy to learn. I give the multiplayer portion of the game an 8.75 out of 10.