Zillion II - The Tri Formation (known as Tri-Formation in Japan)  is a shoot'em up developed by Sega and published by Sega (in North America, Japan and Europe), Korean company Samsung (in Korea) and Brazilian company Tec Toy (in Brazil).

The game is the second tie-in to the anime series Zillion (or Akai Koudan Zillion in Japan). You take the role of JJ, the protagonist of the series. JJ is part of an elite group called the White Knights (White Nuts in the Japanese version) who fight against the invasion of an alien race called Nohza. In this game. JJ must rescue his teammates Apple and Champ from the Nohza Battle Fortress.

There are two gameplay modes which alternate between stages. There are stages with horizontal auto-scrolling where you ride a bike called Tri-Formation. The bike can also transform into a flying mech. You can jump and fire in bike mode. Collecting Z symbols will increase your fire power. In the other stages, you walk around on foot. The game does not auto-scroll in these stages. You can jump and shoot. There are no power-ups to found in these stages, and they end with a boss fight.