Games like Kill Fish
Games like Kill Fish include LIMBO, Hollow Knight, Afterimage, Celeste, and Braid. We matched them by the tags players give Kill Fish on Steam (Side Scroller, Exploration, 2D Platformer, Puzzle Platformer, and Difficult): closest matches first, and among equally close ones the better-known games.

LIMBO
Shared: Puzzle Platformer · Puzzle · Platformer

Hollow Knight
Shared: Difficult · Platformer · Exploration

Afterimage
Shared: 2D Platformer · Side Scroller · Exploration

Celeste
Shared: Difficult · 2D Platformer · Platformer

Braid
Shared: Puzzle Platformer · 2D Platformer · Puzzle

SANABI
Shared: 2D Platformer · Story Rich · Difficult

Momodora: Reverie Under The Moonlight
Shared: Side Scroller · 2D Platformer · Exploration

Hollow Knight: Silksong
Shared: Difficult · Exploration · Platformer

Trine 2: Complete Story
Shared: Puzzle Platformer · 2D Platformer · Platformer

Prince of Persia The Lost Crown
Shared: Exploration · 2D Platformer · Side Scroller

ANIMAL WELL
Shared: Exploration · Puzzle Platformer · Puzzle

Webbed
Shared: 2D Platformer · Exploration · Puzzle Platformer

Portal 2
Shared: Puzzle · Platformer · Puzzle Platformer

Öoo
Shared: Puzzle Platformer · 2D Platformer · Exploration

Touhou Luna Nights
Shared: Side Scroller · Exploration · Difficult

STAR WARS Jedi: Fallen Order™
Shared: Exploration · Action-Adventure · Platformer

Rain World
Shared: Exploration · Difficult · Platformer

Anomaly Agent
Shared: Side Scroller · 2D Platformer · Platformer

Blasphemous 2
Shared: Difficult · Side Scroller · 2D Platformer

Leap Year
Shared: Exploration · 2D Platformer · Puzzle Platformer

The Pedestrian
Shared: Side Scroller · Puzzle Platformer · Puzzle

Ori and the Will of the Wisps
Shared: Platformer · Exploration · Puzzle

Planet of Lana
Shared: Puzzle Platformer · 2D Platformer · Puzzle

Creepy Tale
Shared: Puzzle Platformer · 2D Platformer · Puzzle