Games like Killbox
Games like Killbox include KovaaK's, Drug Dealer Simulator, Aimlabs, Feed and Grow: Fish, and Goat Simulator. We matched them by the tags players give Killbox on Steam (Indie, Action, and Simulation): closest matches first, and among equally close ones the better-known games.

KovaaK's
Shared: Action · Simulation · Indie

Drug Dealer Simulator
Shared: Simulation · Action · Indie

Aimlabs
Shared: Simulation · Action · Indie

Feed and Grow: Fish
Shared: Simulation · Action · Indie

Goat Simulator
Shared: Simulation · Indie · Action

War Thunder
Shared: Action · Simulation

Total Tank Simulator
Shared: Action · Simulation · Indie

The Drone Racing League Simulator
Shared: Action · Simulation · Indie

Project Wingman
Shared: Action · Indie · Simulation

Retrowave
Shared: Indie · Simulation · Action

Session: Skate Sim
Shared: Simulation · Indie · Action

鬼谷八荒 Tale of Immortal
Shared: Simulation · Action · Indie

Papers, Please
Shared: Indie · Simulation

Totally Accurate Battle Simulator
Shared: Simulation · Indie · Action

Skul: The Hero Slayer
Shared: Indie · Action

Russian Life Simulator
Shared: Simulation · Indie · Action

Wreckfest
Shared: Simulation · Action · Indie

Angels Fall First
Shared: Action · Indie · Simulation

Door Kickers
Shared: Simulation · Action · Indie

IRON NEST: Heavy Turret Simulator
Shared: Simulation · Indie · Action

Storm Chasers
Shared: Indie · Simulation · Action

Thief Simulator
Shared: Simulation · Action · Indie

OMON Simulator
Shared: Action · Simulation · Indie

Dinosaur Hunt
Shared: Action · Indie · Simulation