Games like Ostallian Core
Games like Ostallian Core include BALL x PIT, Nova Drift, Cyberhunt, Escape From Duckov, and SYNTHETIK: Legion Rising. We matched them by the tags players give Ostallian Core on Steam (Action, Shooter, Roguelite, Shoot 'Em Up, and Twin Stick Shooter): closest matches first, and among equally close ones the better-known games.
BALL x PIT
Shared: Action · Roguelite · Shoot 'Em Up
Nova Drift
Shared: Shoot 'Em Up · Roguelite · Shooter
Cyberhunt
Shared: Action · Shoot 'Em Up · Twin Stick Shooter
Escape From Duckov
Shared: Action · Shooter · Top-Down Shooter
SYNTHETIK: Legion Rising
Shared: Roguelite · Action · Top-Down Shooter
SNKRX
Shared: Roguelite · Shoot 'Em Up · Top-Down Shooter
Beat Hazard
Shared: Twin Stick Shooter · Shoot 'Em Up · Action
Insect Swarm
Shared: Shooter · Shoot 'Em Up · Twin Stick Shooter
The Ascent
Shared: Action · Top-Down Shooter · Shooter
Halo: Spartan Assault
Shared: Action · Shooter · Top-Down Shooter
Vampire Survivors
Shared: Roguelite · Action · 2D
Bit Blaster XL
Shared: Shooter · Shoot 'Em Up · Action
Rogue Legacy 2
Shared: Action · Roguelite · Arcade
Run Build Pew!
Shared: Roguelite · Shooter · Shoot 'Em Up
Minishoot' Adventures
Shared: Twin Stick Shooter · Top-Down Shooter · Shooter
Greedland
Shared: Roguelite · Shoot 'Em Up · Twin Stick Shooter
Planes, Bullets and Vodka
Shared: Action · Shoot 'Em Up · Shooter
SYNTHETIK 2
Shared: Roguelite · Top-Down Shooter · Twin Stick Shooter
Chippy
Shared: Twin Stick Shooter · Shoot 'Em Up · Shooter
Crimsonland
Shared: Action · Shooter · Top-Down Shooter
12 is Better Than 6
Shared: Action · Shooter · Top-Down Shooter
Relic Hunters Zero: Remix
Shared: Action · Twin Stick Shooter · Top-Down Shooter
Deep Rock Galactic: Survivor
Shared: Roguelite · Top-Down Shooter · Action
Star of Providence
Shared: Roguelite · Shoot 'Em Up · Action