Games like GastroNomicon
Games like GastroNomicon include PUBG: BATTLEGROUNDS, Skul: The Hero Slayer, Phantom Abyss, Dead Cells, and 20 Minutes Till Dawn. We matched them by the tags players give GastroNomicon on Steam (Action, Adventure, Strategy, Action Roguelike, and Battle Royale): closest matches first, and among equally close ones the better-known games.

PUBG: BATTLEGROUNDS
Shared: Battle Royale · Shooter · Action

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

Phantom Abyss
Shared: Action · Adventure · Action Roguelike

Dead Cells
Shared: Adventure · Action Roguelike · Action

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

Orcs Must Die! 2
Shared: Action · Strategy · Tower Defense

Apex Legends™
Shared: Battle Royale · Action · Shooter

Pumpkin Jack
Shared: Action · Adventure · 3D Platformer

Vampire Survivors
Shared: Action Roguelike · Bullet Hell · Action

Megabonk
Shared: Action Roguelike · Action · Bullet Hell

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

ScourgeBringer
Shared: Action · Adventure · Action Roguelike

Escape From Duckov
Shared: Action · Adventure · Shooter

One Step From Eden
Shared: Action Roguelike · Action · Adventure

Pass the Fear
Shared: Action Roguelike · Action · Strategy

Sonic Adventure 2
Shared: Action · Adventure · Platformer

Sonic Frontiers
Shared: Adventure · Action · 3D Platformer

Neon White
Shared: Action · Platformer · 3D Platformer

Grand Theft Auto V Legacy
Shared: Action · Adventure · Shooter

CRYPTARK
Shared: Action · Action Roguelike · Adventure

Crab Champions
Shared: Action Roguelike · Action · Adventure

Nova Drift
Shared: Action Roguelike · Bullet Hell · Action

Risk of Rain 2
Shared: Action Roguelike · Action · Shooter

Hades
Shared: Action Roguelike · Action · Roguelite