Games like Slug Survival
Games like Slug Survival include Megabonk, Brotato, Vampire Survivors, Deep Rock Galactic: Survivor, and 20 Minutes Till Dawn. We matched them by the tags players give Slug Survival on Steam (Arena Shooter, Action Roguelike, Action, Top-Down, and Bullet Hell): closest matches first, and among equally close ones the better-known games.

Megabonk
Shared: Action Roguelike · Bullet Hell · Action

Brotato
Shared: Action Roguelike · Bullet Hell · Singleplayer

Vampire Survivors
Shared: Action Roguelike · Bullet Hell · Singleplayer

Deep Rock Galactic: Survivor
Shared: Action Roguelike · Bullet Hell · Arena Shooter

20 Minutes Till Dawn
Shared: Action Roguelike · Bullet Hell · Survival

Nova Drift
Shared: Action Roguelike · Bullet Hell · Arena Shooter

BALL x PIT
Shared: Action · Action Roguelike · Bullet Hell

Arms of God
Shared: Action Roguelike · Arena Shooter · Bullet Hell

FatalZone
Shared: Action Roguelike · Bullet Hell · Arena Shooter

Enter the Gungeon
Shared: Action Roguelike · Bullet Hell · Action

Rocket Rats
Shared: Action Roguelike · Bullet Hell · Action

Halls of Torment
Shared: Action Roguelike · Bullet Hell · Action

God Of Weapons
Shared: Action Roguelike · Arena Shooter · Bullet Hell

Planes, Bullets and Vodka
Shared: Action · Bullet Hell · Casual

PUBG: BATTLEGROUNDS
Shared: Survival · Shooter · Action

Crab Champions
Shared: Action Roguelike · Bullet Hell · Arcade

Yet Another Zombie Survivors
Shared: Action Roguelike · Top-Down · Singleplayer

Monsters are Coming!
Shared: Action · Top-Down · Action Roguelike

Noobs Want to Live
Shared: Bullet Hell · Action · Action Roguelike

Glyphica: Typing Survival
Shared: Action Roguelike · Arena Shooter · Bullet Hell

The Binding of Isaac
Shared: Action Roguelike · Action · Top-Down

Project Lazarus
Shared: Action Roguelike · Action · Bullet Hell

Nuclear Throne
Shared: Action Roguelike · Action · Bullet Hell

The Last Stand: Aftermath
Shared: Survival · Action Roguelike · Shooter