Games like AquaFantasia
Games like AquaFantasia include Tiny Pasture, Slime Rancher 2, Chillquarium, Farming Simulator 25, and Digseum. We matched them by the tags players give AquaFantasia on Steam (Creature Collector, Simulation, Relaxing, Idler, and Economy): closest matches first, and among equally close ones the better-known games.

Tiny Pasture
Shared: Idler · Creature Collector · Relaxing

Slime Rancher 2
Shared: Relaxing · Creature Collector · Simulation

Chillquarium
Shared: Creature Collector · Idler · Economy

Farming Simulator 25
Shared: Simulation · Farming Sim · Economy

Digseum
Shared: Idler · Simulation · Relaxing

Joyquarium
Shared: Creature Collector · Simulation · Idler

Rusty's Retirement
Shared: Idler · Simulation · Relaxing

Megaquarium
Shared: Simulation · Creature Collector · Relaxing

Your Big, Cute Monster Farm
Shared: Simulation · Creature Collector · Idler

Stardew Valley
Shared: Relaxing · Simulation · Farming Sim

Scritchy Scratchy
Shared: Idler · Relaxing · Simulation

Click the Button
Shared: Simulation · Idler · Casual

Cast n Chill
Shared: Relaxing · Creature Collector · Idler

Fantasy Aquarium
Shared: Relaxing · Idler · Simulation

Cornerpond
Shared: Simulation · Idler · Creature Collector

Shelldiver
Shared: Idler · Relaxing · Simulation

TCG Card Shop Simulator
Shared: Simulation · Economy · Capitalism

Keep on Mining!
Shared: Idler · Relaxing · Capitalism

Tiny Aquarium: Social Fishkeeping
Shared: Creature Collector · Idler · Economy

MyVoiceZoo
Shared: Simulation · Creature Collector · Idler

Spirit City: Lofi Sessions
Shared: Relaxing · Creature Collector · Idler

Big Ambitions
Shared: Simulation · Economy · Capitalism

Budgie's Bug Shop
Shared: Simulation · Idler · Economy

Lyca
Shared: Relaxing · Idler · Simulation