Like the Mario Kart and Mario Strikers series, Mario Paintball Challenge applies a item system for the concept of the sport, so it can become more a Mario-like sport.
There are 16 playable characters in this game.
- Mario - Red paintballs
- Luigi - Dark green paintballs
- Peach - Pink paintballs
- Yoshi - Light green paintballs
- Wario - Purple paintballs
- Waluigi - Dark blue paintballs
- Koopa - Lime paintballs
- Toad - Sky blue paintballs
- Daisy - Orange paintballs
- Boo - Black paintballs
- Rosalina - Teal paintballs
- Shy Guy - White paintballs
- Birdo - Magenta paintballs
- Hammer Bro. - Yellow paintballs
- Dry Bones - Gray paintballs
- Lakitu - Cyan paintballs
These unplayable characters can be either supporting, obstacles or bosses.
P.S: These bosses are only fought if the player chooses 'Boss Mode' in Single-Player or Multi-Player. The bosses for the unlockable stages are bought separatedly.