Games like Indulge
Games like Indulge include Reus, Papers, Please, Game Dev Tycoon, Mountain, and Potion Craft: Alchemist Simulator. We matched them by the tags players give Indulge on Steam (Simulation, God Game, 2D Platformer, 2D, and 1980s): closest matches first, and among equally close ones the better-known games.

Reus
Shared: God Game · Simulation · Indie

Papers, Please
Shared: Simulation · Indie · Singleplayer

Game Dev Tycoon
Shared: Simulation · Indie · 2D

Mountain
Shared: Simulation · God Game · Indie

Potion Craft: Alchemist Simulator
Shared: Simulation · Singleplayer · 2D

Plague Inc: Evolved
Shared: Simulation · Indie · Singleplayer

鬼谷八荒 Tale of Immortal
Shared: Simulation · Singleplayer · 2D

Simmiland
Shared: Simulation · God Game · Indie

Pizza Tower
Shared: 2D Platformer · Indie · Singleplayer

Russian Life Simulator
Shared: Simulation · 2D · Singleplayer

People Playground
Shared: 2D · Simulation · Singleplayer

Beat Cop
Shared: Simulation · Indie · 1980s

Celeste
Shared: 2D Platformer · Indie · 2D

Super Meat Boy
Shared: 2D Platformer · 2D · Indie

Sand:box
Shared: Simulation · God Game · 2D

The Escapists
Shared: Simulation · 2D · Singleplayer

911 Operator
Shared: Simulation · Indie · Singleplayer

WorldBox - God Simulator
Shared: God Game · Simulation · Indie

SANABI
Shared: 2D Platformer · 2D · Singleplayer

龙胤立志传
Shared: Simulation · Turn-Based Combat · Singleplayer

Retrowave
Shared: 1980s · Simulation · Indie

Doodle God
Shared: God Game · Simulation · Indie

Cyber Manhunt
Shared: Simulation · Indie · Singleplayer

Hollow Knight: Silksong
Shared: 2D · Indie · Singleplayer