Games like IDLE PET UFO
Games like IDLE PET UFO include Tiny Pasture, Shelldiver, Stardew Valley, Digseum, and Unpacking. We matched them by the tags players give IDLE PET UFO on Steam (Relaxing, Atmospheric, Simulation, Idler, and 2D): closest matches first, and among equally close ones the better-known games.

Tiny Pasture
Shared: Idler · Cute · Relaxing

Shelldiver
Shared: Relaxing · Idler · Simulation

Stardew Valley
Shared: Relaxing · Simulation · Pixel Graphics

Digseum
Shared: Idler · Relaxing · Simulation

Unpacking
Shared: Relaxing · Cute · Pixel Graphics

Cast n Chill
Shared: Relaxing · Idler · Atmospheric

Slime Rancher 2
Shared: Relaxing · Cute · Simulation

Cookie Clicker
Shared: Idler · Incremental · Pixel Graphics

Click the Button
Shared: Idler · Simulation · Pixel Graphics

Nodebuster
Shared: Idler · Simulation · 2D

Rusty's Retirement
Shared: Idler · Relaxing · Simulation

Chill with You : Lo-Fi Story
Shared: Relaxing · Atmospheric · Idler

Cornerpond
Shared: Idler · Simulation · Relaxing

Sticky Business
Shared: Relaxing · Simulation · Cute

Placid Plastic Duck Simulator
Shared: Relaxing · Cute · Simulation

Click and Conquer
Shared: Simulation · Relaxing · Idler

A Game About Feeding A Black Hole
Shared: Relaxing · Idler · Simulation

Screen Cat
Shared: Relaxing · Cute · Idler

Fantasy Aquarium
Shared: Relaxing · Idler · Cute

Chillquarium
Shared: Idler · Incremental · Relaxing

Webbed
Shared: Cute · Relaxing · Pixel Graphics

GRIS
Shared: Atmospheric · Relaxing · Hand-drawn

Fischer's Fishing Journey
Shared: Idler · Relaxing · Cute

Fields of Mistria
Shared: Simulation · Pixel Graphics · Relaxing