PD Ultraman Invader is a title released in 1995 for the PlayStation in Japan only. The game was developed by Bandai under license from Taito. As it's name implies this game is a Ultraman-themed Space Invaders spin-off. Two modes are available: Ultraman Mode (ウルトラマンモード) and Original Mode (オリジナルモード), which is a port of the original Space Invaders game with both single player and two-player versus gameplay modes.
Ultraman Mode features three different gameplay modes. Story Mode (ヒストリーモード) is the main game, where you complete stages and defeat bosses. Through Mode (とことんモード) is a survival/time attack mode while the Versus Mode (対戦モード) allows for two players to compete against each other. In Ultraman Mode the Core Cannon is replaced by one of various different Ultramen depending on the stage, while the enemies are replaced with monsters from the show, with all sprites done in a pre-rendered super-deformed style. The UFO is replaced by a flying Ultraman, which will drop power-ups when shot.
The game is played from a oblique view point, with the stage scrolling left and right as you move to those directions instead of being a single fixed screen. When only one enemy is left on the screen, this enemy will power itself up, taking multiple hits to be defeated, but sometimes it will multiply itself, tasking the player with shooting the right one to cause damage.