This game is fun even alone...
There are great characters in this like Wendy, Slash, Jam, Nancy (my favorite), Linda and Damien. The players have different skills. Slash is a balanced player. His controlling is not easy nor hard to pick up and play with. His tricks are in the middle too as is his speed. Nancy, a skill-based player has greater air and excellent turning but her speed is lesser of that balanced or speed-based player. Linda, a speed-based character is for the advanced players only - she's fast, but her turning flat out sucks and she doesn't get as much air as the other types either.
There are bosses, great items like the Pan that falls on everyone but yourself and slows them down and one of my favorites, the Parachute which throws an opponent in the air and slowly, slowly, slowly brings them back to the earth. Very annoying (for them). =)
Anyway, the sound is great and the graphics are pretty good for a N64 game. The surroundings are alright looking but the characters are very cute and charming. Controls are good once you know how to do tricks and know how to reflect oncoming weapons back at the user and tricks like that.
Learning Curve: 15-30 minutes.
Graphics: 8.5/10
Sound: 9/10
Controls: 9.5/10
Game play and Fun: Alone: 7.5/10 Multiplayer: 8-9.5/10 (depending on how many players)
Overall: 9.5/10