Thunder Force II is a two-dimensional futuristic shooter that alternates between top view and side view with the passing of each level. The action takes place in the Lone Star System amongst ancient ruins, skyscrapers, caves, and an underground city. While piloting your super powerful fighter, your objective is to shoot everything in sight. There are four standard levels of play, each with two stages. At the end of each level, you must defeat a giant boss. The bosses names are Kiyara, Zoetrope, Galileo, Elephant Man. The fifth and final level is called the Ultra Combat Weapon Fortress. Here you must face a boss called the Humanoid Hunter.In the top view levels you can upgrade your weapon to Twin-shot, Back Fire, Five Wave, Destroy, Wide Shot, Hunter, Clash, or Laser. The side view level special weapons are Twin-shot, Back Fire, Laser, Hunter, Wave Shot, Side Blaster, Nova, and Mega Flash. The final Ultra Combat level adds a few extra weapons: the Claw and the Breaker create force fields around your ship, and the Roll momentarily boosts your speed.