|Bullet Hell||A sub-genre of shmup where the whole screen is literally filled with projectiles, usually with the main challenge being avoiding those bullets (often by recognizing/memorizing firing patterns) rather than destroying enemies.||1993 / 2017||128 games|
|Multi-directional shooter||A shooter sub-genre defined by open two dimensional environment with freedom of orientation and movement.||1982 / 2018||94 games|
|Run and Gun||Shoot 'em up sub-genre, with both horizontal or vertical scrolling that don't scroll back.||1980 / 2018||746 games|
|Scrolling shooter||A shooter sub genre characterized by automatically advancing (autoscrolling) environments, giving the impression of constant motion towards the goal, preventing any significant backtracking and limiting chances on full destruction of enemy forces.||1980 / 2018||1179 games|
|Tube shooter||Shmup sub-genre where player moves alongside the inside surface of an abstract tube.||1979 / 2016||53 games|
Shoot 'em up
Informal group for finding shmup sub-genres.