Games like I am Neutron
Games like I am Neutron include People Playground, Garry's Mod, Vampire Survivors, Goat Simulator, and Gang Beasts. We matched them by the tags players give I am Neutron on Steam (Casual, Physics, Collectathon, Action-Adventure, and 2D): closest matches first, and among equally close ones the better-known games.

People Playground
Shared: Physics · 2D · Funny

Garry's Mod
Shared: Physics · Casual · Funny

Vampire Survivors
Shared: 2D · Casual · Action Roguelike

Goat Simulator
Shared: Physics · Funny · Casual

Gang Beasts
Shared: Physics · Funny · Casual

Totally Accurate Battle Simulator
Shared: Physics · Funny · Simulation

Placid Plastic Duck Simulator
Shared: Collectathon · Physics · Casual

Cookie Clicker
Shared: Casual · Collectathon · Funny

WHAT THE GOLF?
Shared: Physics · Funny · Casual

Passpartout: The Starving Artist
Shared: Casual · Funny · Simulation

Noita
Shared: Physics · 2D · Roguelike

Slackers - Carts of Glory
Shared: Casual · Physics · Funny

Stick Fight: The Game
Shared: Funny · Physics · Casual

Donut County
Shared: Casual · Physics · Funny

Turbo Dismount™
Shared: Physics · Funny · Simulation

MECCHA CHAMELEON
Shared: Casual · Funny · Hand-drawn

Zup! S
Shared: Casual · Physics · 2D

Game Dev Tycoon
Shared: Casual · Simulation · 2D

CHUCHEL
Shared: Casual · Funny · Colorful

Skul: The Hero Slayer
Shared: 2D · Action · Indie

Golf With Your Friends
Shared: Casual · Funny · Physics

Getting Over It with Bennett Foddy
Shared: Physics · Funny · Casual

Kingdom Rush - Tower Defense
Shared: Casual · 2D · Funny

Unfair Flips
Shared: Casual · 2D · Colorful