Touhou Boueigun is a top down shooter, the gameplay is inspired by Chikyuu Boueigun, a popular 3D shooter series developed by Sandlot. In Touhou Boueigun the player engages with floods of enemies on gigantic sprawling maps before the health runs out. Player unlock new weapons and spells throughout the game by picking up Weapon objects, dropped by killed enemies or upon mission completion.
Here´s gameplay video by Magiftw
Note – If you have difficulty interpreting the text use the translator.