Single player is HARD and frusterating, but decent game for multitap owners.
Another annoyance is that the game where you run around freely and pick up crates to throw at people... You can only throw in 45 degree angles, which gets annoying.
Otherwise it's pretty decent. You start out with four gametypes (with four maps per gametype). Each map has slightly different rules and little things added on.
There's Crate Crush (I think that's it's name), where you run around, pick up fruit for health, and throw crates at other people. One of the other map types for this one is where the floor will fall if you explode a red or green crate (TNT or Nitro).
Also, a game that's kind of like four-way pong. Different map-types have things like magnetism to hold the balls for a bit then launch them quickly, or a tilting map.
Polar Panic(?) is where everyone rides polar bears and tries to shove everyone else off the ice. There's a map where the ice melts, one where it tilts, and one where it has an ice wall all around you have to break down.
Pogo Panic(?) is where you hop around on a square grid, and each person has a color. When you jump on a square you color it, then you hit a purple box to "bank" your points. Person with the most points wins. There are several different maps but it's hard to explain.
The only other gametypes I've unlocked are a racing game (kind of like those old 2D top-down racing games), and a bomberman-ish game with tanks.
Anyways. If you're looking for games for your multitap, this is probably like $10 somewhere and decent enough to keep friends entertained.