Games like Molluscarium
Games like Molluscarium include Spirit City: Lofi Sessions, Chillquarium, Cast n Chill, Tiny Pasture, and Cornerpond. We matched them by the tags players give Molluscarium on Steam (Creature Collector, Idler, Desktop Companion, Cozy, and Relaxing): closest matches first, and among equally close ones the better-known games.

Spirit City: Lofi Sessions
Shared: Desktop Companion · Cozy · Creature Collector

Chillquarium
Shared: Creature Collector · Idler · Collectathon

Cast n Chill
Shared: Idler · Relaxing · Creature Collector

Tiny Pasture
Shared: Idler · Creature Collector · Incremental

Cornerpond
Shared: Idler · Desktop Companion · Creature Collector

Ropuka's Idle Island
Shared: Idler · Desktop Companion · Cozy

Fish to Dish: Idle Sushi
Shared: Idler · Desktop Companion · Creature Collector

How to Train Your Cock
Shared: Idler · Desktop Companion · Cozy

Cookie Clicker
Shared: Idler · Incremental · Collectathon

Kabuto Park
Shared: Creature Collector · Cozy · Relaxing

Joyquarium
Shared: Creature Collector · Idler · Relaxing

Keep on Mining!
Shared: Idler · Incremental · Relaxing

Shelldiver
Shared: Incremental · Idler · Relaxing

Chonkers
Shared: Creature Collector · Idler · Cozy

Lakeside Bar
Shared: Idler · Desktop Companion · Cozy

Slime Rancher 2
Shared: Relaxing · Creature Collector · Cute

Rusty's Retirement
Shared: Idler · Desktop Companion · Relaxing

Digseum
Shared: Idler · Incremental · Relaxing

Birdwatching Notebook
Shared: Idler · Creature Collector · Desktop Companion

My Little Life
Shared: Idler · Desktop Companion · Creature Collector

Ithya: Magic Studies
Shared: Idler · Desktop Companion · Cozy

Garden Galaxy
Shared: Idler · Cozy · Relaxing

Croakoloco
Shared: Creature Collector · Idler · Incremental

Creature Kitchen
Shared: Creature Collector · Cozy · Relaxing