Games like Mystopia
Games like Mystopia include Tiny Glade, Garden Galaxy, My Dream Setup, Townscaper, and Hozy. We matched them by the tags players give Mystopia on Steam (Relaxing, Sandbox, Casual, Building, and Idler): closest matches first, and among equally close ones the better-known games.

Tiny Glade
Shared: Relaxing · Building · Sandbox

Garden Galaxy
Shared: Sandbox · Idler · Relaxing

My Dream Setup
Shared: Relaxing · Building · Sandbox

Townscaper
Shared: Relaxing · Sandbox · Building

Hozy
Shared: Relaxing · Casual · Sandbox

House Flipper
Shared: Relaxing · Building · Sandbox

SUMMERHOUSE
Shared: Relaxing · Sandbox · Casual

Small Spaces
Shared: Relaxing · Building · Sandbox

LEGO® Builder's Journey
Shared: Relaxing · Casual · Cute

Garry's Mod
Shared: Sandbox · Building · Casual

The Sims™ 4
Shared: Building · Sandbox · Relaxing

Paralives
Shared: Building · Sandbox · Relaxing

Unpacking
Shared: Relaxing · Casual · Cute

Ropuka's Idle Island
Shared: Relaxing · Idler · Casual

Town to City
Shared: Building · Relaxing · Cozy

Slime Rancher 2
Shared: Relaxing · Cute · Casual

Planet Coaster
Shared: Sandbox · Building · Relaxing

Panelka
Shared: Casual · Relaxing · Building

Creature Kitchen
Shared: Relaxing · Cozy · Cute

Tiny Pasture
Shared: Idler · Cute · Casual

Stardew Valley
Shared: Relaxing · Sandbox · Building

Furnish Master
Shared: Sandbox · Building · Relaxing

Cloud Gardens
Shared: Sandbox · Relaxing · Nature

Spirit City: Lofi Sessions
Shared: Relaxing · Cozy · Idler