Games like Sine Mora EX
Games like Sine Mora EX include Bit Blaster XL, Touhou Luna Nights, Touhou Koumakyou: New Classic - the Embodiment of Scarlet Devil, Giana Sisters: Twisted Dreams, and Assault Android Cactus+. We matched them by the tags players give Sine Mora EX on Steam (Side Scroller, Shoot 'Em Up, Bullet Hell, Difficult, and Arcade): closest matches first, and among equally close ones the better-known games.

Bit Blaster XL
Shared: Shoot 'Em Up · Bullet Hell · Difficult

Touhou Luna Nights
Shared: Side Scroller · Bullet Hell · Difficult

Touhou Koumakyou: New Classic - the Embodiment of Scarlet Devil
Shared: Shoot 'Em Up · Bullet Hell · Difficult

Giana Sisters: Twisted Dreams
Shared: Side Scroller · Difficult · Arcade

Assault Android Cactus+
Shared: Bullet Hell · Shoot 'Em Up · Difficult

Touhou Tenkuushou ~ Hidden Star in Four Seasons.
Shared: Bullet Hell · Shoot 'Em Up · Difficult

Ikaruga
Shared: Shoot 'Em Up · Bullet Hell · Arcade

Jets'n'Guns Gold
Shared: Shoot 'Em Up · Side Scroller · Bullet Hell

Kero Blaster
Shared: Side Scroller · Shoot 'Em Up · Difficult

Mushihimesama
Shared: Shoot 'Em Up · Bullet Hell · Arcade

Sine Mora
Shared: Shoot 'Em Up · Bullet Hell · Side Scroller

Nova Drift
Shared: Shoot 'Em Up · Bullet Hell · Arcade

Warhammer 40,000: Shootas, Blood & Teef
Shared: Side Scroller · PvP · Shoot 'Em Up

ZeroRanger
Shared: Shoot 'Em Up · Bullet Hell · Arcade

DRAINUS
Shared: Shoot 'Em Up · Shooter · Bullet Hell

Touhou Kinjoukyou ~ Fossilized Wonders.
Shared: Shoot 'Em Up · Bullet Hell · Shooter

METAL SLUG
Shared: Side Scroller · Shoot 'Em Up · Arcade

R-Type Final 2
Shared: Shoot 'Em Up · Side Scroller · Arcade

DARIUSBURST Chronicle Saviours
Shared: Shoot 'Em Up · Side Scroller · Arcade

Touhou Juuouen 〜 Unfinished Dream of All Living Ghost.
Shared: Shoot 'Em Up · Bullet Hell · Shooter

METAL SLUG 3
Shared: Side Scroller · Arcade · Shooter

Revolution Ace
Shared: Shoot 'Em Up · Bullet Hell · Shooter

Blazing Chrome
Shared: Side Scroller · Shoot 'Em Up · Arcade

Huntdown
Shared: Side Scroller · Shoot 'Em Up · Shooter