Crisis Force

Developed by Konami and released in 1991 exclusively for the Famicom in Japan, Crisis Force is a vertically scrolling shoot-em-up starring two shrine maiden sisters who pilot transforming fighter craft against an invading alien army. The game supports two-player simultaneous co-op, and each ship can freely switch among three distinct forms, each providing a different spread pattern and attack style. Crisis Force is renowned for pushing the Famicom hardware to its absolute limits, delivering multi-layer parallax scrolling backgrounds and dense on-screen explosion effects that were remarkable for the platform. It is widely regarded as one of the finest shoot-em-ups ever released for the system.