U.N. Defense Force: Earth Joker

Earth Joker is a vertical shooter from Visco/Taito
The year is 2036. The Earth has been invaded by the hostile Slytow. As one of a select team, it is your task to take back the Earth! Having secured the Atlantic Ocean as a base of operations in 2034, we feel confident that you can accomplish your mission.
Developed by Visco Games in 1993, Earth Joker is a vertical shmup with some rather clever ideas. There’s a coherant story, played through the intro, and small cut-scenes. Each player can choose one of four characters, without duplication. Each ship has a charge shot, a main shot, and a recharging bomb. There are also sub-weapons that can be changed out via pickups. These include homing missiles, dumbfire missles, grenades, and side-firing missiles.