Most satisfying projectile combat/shooting

[Leynos]

Contra III

Gungrave/Gungrave GORE

Assault Suit Leynos

Assault Suits Valken

Raiden series

Ikaruga

Space Marine 1-2

Binary Domain

Turbo Overkill

Gears 1-4.

VanQuish

Doom 2016

Prodeus

Anything from Toaplan

MUSHA

Bulletstorm

BT in Titanfall 2

Rage 2

If I thought about it can name a bunch more FPS,side scrolling run n guns. Shmups. Too many for me think of off the top of my head.