Games like Zen Aquarium
Games like Zen Aquarium include Cast n Chill, Slime Rancher 2, Spirit City: Lofi Sessions, DAVE THE DIVER, and Chillquarium. We matched them by the tags players give Zen Aquarium on Steam (Simulation, Underwater, Cozy, Relaxing, and Idler): closest matches first, and among equally close ones the better-known games.

Cast n Chill
Shared: Relaxing · Cozy · Idler

Slime Rancher 2
Shared: Relaxing · Simulation · Colorful

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

DAVE THE DIVER
Shared: Relaxing · Casual · Underwater

Chillquarium
Shared: Idler · Cozy · Creature Collector

Kabuto Park
Shared: Cozy · Nature · Casual

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

Leafy Corner
Shared: Cozy · Simulation · Relaxing

Tiny Glade
Shared: Relaxing · Cozy · Casual

Mountain
Shared: Simulation · Relaxing · Casual

Dressmaker
Shared: Cozy · Simulation · Relaxing

DrainSim
Shared: Simulation · Relaxing · Casual

Hozy
Shared: Cozy · Relaxing · Simulation

LurkBait Twitch Fishing
Shared: Simulation · Idler · Creature Collector

PowerWash Simulator
Shared: Simulation · Relaxing · Casual

Joyquarium
Shared: Simulation · Idler · Relaxing

Loddlenaut
Shared: Underwater · Relaxing · Cozy

Hello Kitty Island Adventure
Shared: Cozy · Simulation · Relaxing

Burgie's Cozy Kitchen
Shared: Simulation · Relaxing · Idler

Minami Lane
Shared: Simulation · Relaxing · Casual

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

Ballads of Hongye: REBORN
Shared: Simulation · Relaxing · Casual

ABZU
Shared: Underwater · Relaxing · Casual

Cornerpond
Shared: Simulation · Idler · Relaxing