Games like Protect the Grimoire
Games like Protect the Grimoire include Vampire Survivors, BALL x PIT, 20 Minutes Till Dawn, Balatro, and Nova Drift. We matched them by the tags players give Protect the Grimoire on Steam (Shoot 'Em Up, Bullet Hell, Roguelite, Roguelike, and Strategy): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Bullet Hell · Roguelite · 2D

BALL x PIT
Shared: Roguelite · Bullet Hell · Shoot 'Em Up

20 Minutes Till Dawn
Shared: Bullet Hell · Shoot 'Em Up · Roguelite

Balatro
Shared: Roguelike · Strategy · Roguelite

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

Megabonk
Shared: Roguelite · Roguelike · Bullet Hell

Halls of Torment
Shared: Bullet Hell · Roguelite · Roguelike

Death Must Die
Shared: Bullet Hell · Roguelite · Roguelike

Star of Providence
Shared: Bullet Hell · Roguelite · Shoot 'Em Up

Brotato
Shared: Bullet Hell · Roguelike · Roguelite

Greedland
Shared: Shoot 'Em Up · Roguelite · Bullet Hell

Slots & Daggers
Shared: Strategy · Roguelike · Roguelite

I Am Legion: Stand Survivors
Shared: Bullet Hell · Shoot 'Em Up · Roguelite

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

Skul: The Hero Slayer
Shared: Roguelike · Roguelite · Action

Dead Cells
Shared: Roguelike · Roguelite · 2D

Pass the Fear
Shared: Roguelite · Bullet Hell · Roguelike

Soulstone Survivors
Shared: Roguelite · Bullet Hell · Roguelike

Octogeddon
Shared: Shoot 'Em Up · Strategy · Action

Apocalypse Party
Shared: Bullet Hell · Shoot 'Em Up · Roguelite

Tower of Babel: Survivors of Chaos
Shared: Bullet Hell · Roguelite · Roguelike

Astro Prospector
Shared: Roguelike · Roguelite · Bullet Hell

Hades
Shared: Roguelite · Roguelike · Action

Boneraiser Minions
Shared: Bullet Hell · Roguelite · 2D