Games like Inertia
Games like Inertia include Gorilla Tag, VHOLUME, Clustertruck, Refunct, and SpeedRunners. We matched them by the tags players give Inertia on Steam (Casual, Competitive, Tutorial, 3D Platformer, and 3D): closest matches first, and among equally close ones the better-known games.

Gorilla Tag
Shared: Parkour · 3D · 3D Platformer

VHOLUME
Shared: Casual · Parkour · 3D Platformer

Clustertruck
Shared: Parkour · 3D Platformer · Action

Refunct
Shared: 3D Platformer · Casual · Parkour

SpeedRunners
Shared: Competitive · Casual · Multiplayer

Exertus
Shared: Casual · 3D Platformer · Tutorial

PowerWash Simulator
Shared: Casual · 3D · First-Person

Haste
Shared: 3D Platformer · Parkour · Action

Marvel Rivals
Shared: Competitive · Casual · Multiplayer

DJMAX RESPECT V
Shared: Casual · Competitive · Action

FOTONICA
Shared: Abstract · Action · Parkour

A Story About My Uncle
Shared: Parkour · 3D Platformer · Casual

SEUM: Speedrunners from Hell
Shared: 3D Platformer · Parkour · Level Editor

Liars Bar
Shared: Casual · 3D · Multiplayer

Neon White
Shared: 3D Platformer · Parkour · Action

Mirror's Edge™ Catalyst
Shared: Parkour · 3D Platformer · Runner

Pseudoregalia
Shared: 3D Platformer · Parkour · 3D

A Dance of Fire and Ice
Shared: Level Editor · Casual · Difficult

Only Up: With Friends
Shared: Casual · Parkour · 3D Platformer

s&box
Shared: Casual · 3D Platformer · 3D

Bomb Rush Cyberfunk
Shared: 3D Platformer · Parkour · Action

Intralism
Shared: Level Editor · Casual · Indie

Ultimate Chicken Horse
Shared: Level Editor · Multiplayer · Competitive

Geometry Dash
Shared: Level Editor · Difficult · Platformer