Games like Gob Johnson's Downhill Marmalade
Games like Gob Johnson's Downhill Marmalade include Vampire Survivors, Skul: The Hero Slayer, Dead Cells, The Binding of Isaac: Rebirth, and Megabonk. We matched them by the tags players give Gob Johnson's Downhill Marmalade on Steam (Action, Action Roguelike, Arcade, Roguelike, and Roguelite): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Action Roguelike · Roguelite · Pixel Graphics

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

Dead Cells
Shared: Action Roguelike · Roguelike · 2D

The Binding of Isaac: Rebirth
Shared: Action Roguelike · Roguelike · Pixel Graphics

Megabonk
Shared: Action Roguelike · Roguelike · Roguelite

BALL x PIT
Shared: Action · Arcade · Roguelite

Rogue Legacy
Shared: Action Roguelike · Roguelike · Action

Halls of Torment
Shared: Action Roguelike · Roguelite · Action

Hades
Shared: Action Roguelike · Roguelite · Action

Dungreed
Shared: Action Roguelike · Action · Roguelike

Sephiria
Shared: Action Roguelike · Roguelike · Roguelite

The Binding of Isaac
Shared: Action Roguelike · Roguelike · Action

Death Must Die
Shared: Action Roguelike · Roguelite · Action

UnderMine
Shared: Action Roguelike · Roguelite · Action

Streets of Rogue
Shared: Action Roguelike · Roguelite · Action

Enter the Gungeon
Shared: Action Roguelike · Roguelike · Pixel Graphics

Wizard of Legend
Shared: Action Roguelike · Roguelike · Action

Risk of Rain (2013)
Shared: Action Roguelike · Roguelike · Action

Hades II
Shared: Action · Roguelike · Roguelite

Boneraiser Minions
Shared: Action Roguelike · Roguelite · Pixel Graphics

Nuclear Throne
Shared: Action Roguelike · Roguelike · Action

Rogue Legacy 2
Shared: Arcade · Action · Roguelite

ScourgeBringer
Shared: Action · Action Roguelike · Roguelite

Noita
Shared: Roguelike · Pixel Graphics · 2D