Plot: Strikers 1999, also known as Strikers 1945 III, is a vertically-scrolling shoot 'em up game developed and originally released by Psikyo in 1999 for the arcades. The game is a sequel to Strikers 1945 II, chronologically taking place 54 years after the first two games in the series. Wikipedia
Plot: Strikers 1945 II is a vertically-scrolling shoot 'em up game developed and originally published by Psikyo in 1997 for the arcades as a follow-up to Strikers 1945. This game was also ported by Kuusou Kagaku to the PlayStation and Sega Saturn for Psikyo and re-released by Success in 2000. Wikipedia
Plot: Gunbird 2 is a 2D scrolling shooter developed by Psikyo and published by Capcom as a sequel to the original Gunbird. It was originally released in Japanese arcades in 1998, and was later ported to the Dreamcast in 2000 and released worldwide. Wikipedia