Bangai-O is a shoot 'em up video game produced by Treasure Co. Ltd. It was first released on the Nintendo 64 (N64) and later ported to the Dreamcast (DC).

Bangai-O in its English language release, or Bakuretsu Muteki Bangaioh (Explosive, Invincible Bangaioh) in Japan has all the innovation that has built Treasure its repuation as one of the worlds best regarded developers.

Initially looking like an Amiga game (the small sprites recall Team 17's Worms, for example), the innovation in the title only becomes apparent once the controller is picked up. Controls are like a cross between Thrust - your mecha is affected by gravity and needs to be pushed into the air - and Robotron - eight-way directional controls on the pad's cross and independent eight-way weapon controls on the four facia buttons. Your mech has two firing modes. By switching between the two siblings piloting the Bangai-O, you could fire either homing missiles or reflective lasers that bounced off walls.

The game's main draw is its special attack. The power of your smart bomb depends on how many enemy bullets are on the screen and how close you are to them when you fire it. Hit it at exactly the right time and you can fire up to 400 shots at once.

The English language version also features some of the most messed-up Engrish around.