Games like Idle Rect
Games like Idle Rect include Cookie Clicker, Game Dev Tycoon, Nodebuster, Planet Coaster, and Loot Loop. We matched them by the tags players give Idle Rect on Steam (Indie, Idler, Incremental, Sandbox, and Simulation): closest matches first, and among equally close ones the better-known games.

Cookie Clicker
Shared: Idler · Incremental · Indie

Game Dev Tycoon
Shared: Indie · Simulation · Management

Nodebuster
Shared: Incremental · Idler · Strategy

Planet Coaster
Shared: Simulation · Sandbox · Management

Loot Loop
Shared: Incremental · Idler · Simulation

A Game About Feeding A Black Hole
Shared: Incremental · Indie · Idler

Cities: Skylines
Shared: Simulation · Sandbox · Strategy

IdleOn - The Incremental MMO
Shared: Idler · Incremental · Management

(the) Gnorp Apologue
Shared: Idler · Incremental · Strategy

Startup Company
Shared: Indie · Simulation · Management

Shelldiver
Shared: Incremental · Idler · Management

Dragon Cliff
Shared: Idler · Incremental · Strategy

Banished
Shared: Indie · Simulation · Strategy

Idle Champions of the Forgotten Realms
Shared: Idler · Incremental · Strategy

Totally Accurate Battle Simulator
Shared: Sandbox · Simulation · Indie

Mini Motorways
Shared: Simulation · Strategy · Indie

Prison Architect
Shared: Simulation · Sandbox · Strategy

鬼谷八荒 Tale of Immortal
Shared: Simulation · Management · Sandbox

Foundation
Shared: Simulation · Sandbox · Strategy

Keep on Mining!
Shared: Idler · Incremental · Indie

Bills Must Be Paid
Shared: Incremental · Idler · Indie

Cities: Skylines II
Shared: Simulation · Sandbox · Management

Digseum
Shared: Incremental · Idler · Simulation

RimWorld
Shared: Sandbox · Strategy · Management