Games like Swarmfall
Games like Swarmfall include Nova Drift, Deep Rock Galactic: Survivor, Vampire Survivors, SNKRX, and Star of Providence. We matched them by the tags players give Swarmfall on Steam (Arena Shooter, Bullet Hell, Shoot 'Em Up, Roguelite, and PvE): closest matches first, and among equally close ones the better-known games.
Nova Drift
Shared: Bullet Hell · Shoot 'Em Up · Roguelite
Deep Rock Galactic: Survivor
Shared: Bullet Hell · Roguelite · Arena Shooter
Vampire Survivors
Shared: Bullet Hell · Roguelite · 2D
SNKRX
Shared: Arena Shooter · Roguelite · Shoot 'Em Up
Star of Providence
Shared: Bullet Hell · Roguelite · Shoot 'Em Up
X Invader
Shared: Arena Shooter · Shoot 'Em Up · Bullet Hell
20 Minutes Till Dawn
Shared: Bullet Hell · Roguelite · Shoot 'Em Up
BALL x PIT
Shared: Bullet Hell · Roguelite · Shoot 'Em Up
Time Wasters
Shared: Bullet Hell · Arena Shooter · Roguelite
Bit Blaster XL
Shared: Bullet Hell · Shoot 'Em Up · Shooter
Star Saviors
Shared: Bullet Hell · Shoot 'Em Up · Strategy
Rogue: Genesia
Shared: Bullet Hell · Roguelite · PvE
Brotato
Shared: Bullet Hell · Arena Shooter · Roguelite
Glyphica: Typing Survival
Shared: Arena Shooter · Bullet Hell · Roguelite
Touhou Kouryudou ~ Unconnected Marketeers.
Shared: Bullet Hell · Shoot 'Em Up · Shooter
HELLDIVERS™ 2
Shared: PvE · Shooter · Action
Slime 3K: Rise Against Despot
Shared: Bullet Hell · Roguelite · Shoot 'Em Up
Chippy
Shared: Bullet Hell · Arena Shooter · Shoot 'Em Up
Greedland
Shared: Shoot 'Em Up · Bullet Hell · Roguelite
Pass the Fear
Shared: Bullet Hell · Roguelite · Shooter
I Am Legion: Stand Survivors
Shared: Bullet Hell · Shoot 'Em Up · Roguelite
ZeroRanger
Shared: Shoot 'Em Up · Bullet Hell · Shooter
Bloodshed
Shared: Bullet Hell · Arena Shooter · Roguelite
Touhou Koumakyou: New Classic - the Embodiment of Scarlet Devil
Shared: Bullet Hell · Shoot 'Em Up · Shooter