Games like Don't kill the fish
Games like Don't kill the fish include Shelldiver, Cookie Clicker, Digseum, Click the Button, and Nodebuster. We matched them by the tags players give Don't kill the fish on Steam (Incremental, Idler, Rhythm, Perma Death, and Point & Click): closest matches first, and among equally close ones the better-known games.

Shelldiver
Shared: Incremental · Idler · Casual

Cookie Clicker
Shared: Incremental · Idler · Casual

Digseum
Shared: Incremental · Idler · Casual

Click the Button
Shared: Incremental · Idler · Casual

Nodebuster
Shared: Incremental · Idler · Casual

Tiny Pasture
Shared: Idler · Incremental · Cute

A Game About Feeding A Black Hole
Shared: Incremental · Idler · Casual

Keep on Mining!
Shared: Incremental · Idler · Casual

Click and Conquer
Shared: Incremental · Idler · Casual

Tower Wizard
Shared: Incremental · Idler · 2D

Unpacking
Shared: Casual · Cute · Relaxing

Cornerpond
Shared: Idler · Incremental · Simulation

Incredicer
Shared: Incremental · Idler · Casual

Fortune Mill
Shared: Incremental · Idler · Casual

Horripilant
Shared: Incremental · Idler · Casual

(the) Gnorp Apologue
Shared: Incremental · Idler · Cute

Loot Loop
Shared: Incremental · Idler · Casual

Fantasy Aquarium
Shared: Idler · Incremental · Casual

Plantera
Shared: Incremental · Idler · Point & Click

Muse Dash
Shared: Rhythm · Cute · Casual

A Little to the Left
Shared: Relaxing · Point & Click · Casual

Scratchers
Shared: Incremental · Idler · Casual

Scritchy Scratchy
Shared: Incremental · Idler · Relaxing

Sticky Business
Shared: Casual · Relaxing · Cute