Touhou - Shoot the Bullet (Touhou 9.5)

In Shoot the Bullet, you play as Aya Shameimaru as she photographs the bosses from various Touhou games. However, no one ever reveals the reason for these, and in fact at one point it is pointed out that "No one knows the purpose of the photos, except Aya," and the only reason she does not shoot the opponents is "not to be nice, but because she doesn't want her bullets in the picture."

Many aspects of Shoot the Bullet are similar to more traditional shmups, so the skills learned by playing other Touhou games do transfer to a certain extent. However, game elements like the use of film-reloading and defensive shots require some technique over and above standard dodging and streaming skills.

It's a damn fun game, especially if you need some variation from the other touhou games.