Games like Slap The Fly
Games like Slap The Fly include Garry's Mod, KovaaK's, One-armed robber, Plague Inc: Evolved, and Gang Beasts. We matched them by the tags players give Slap The Fly on Steam (Indie, Simulation, Multiplayer, FPS, and Funny): closest matches first, and among equally close ones the better-known games.

Garry's Mod
Shared: Multiplayer · Funny · Simulation

KovaaK's
Shared: Simulation · Indie · FPS

One-armed robber
Shared: Multiplayer · Simulation · FPS

Plague Inc: Evolved
Shared: Simulation · Indie · Multiplayer

Gang Beasts
Shared: Multiplayer · Funny · Indie

Totally Accurate Battle Simulator
Shared: Simulation · Funny · Indie

Golf With Your Friends
Shared: Multiplayer · Indie · Funny

Internet Cafe Simulator
Shared: Indie · Simulation · Multiplayer

Squad 44
Shared: Simulation · FPS · Multiplayer

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

Viscera Cleanup Detail
Shared: Simulation · Multiplayer · Indie

Golf It!
Shared: Multiplayer · Funny · Simulation

Two Point Hospital
Shared: Simulation · Funny · Indie

Ready or Not
Shared: FPS · Multiplayer · Singleplayer

Waterpark Simulator
Shared: Simulation · Multiplayer · Singleplayer

House Flipper
Shared: Simulation · Multiplayer · Singleplayer

Who's Your Daddy?!
Shared: Multiplayer · Funny · Simulation

Hand Simulator
Shared: Simulation · Multiplayer · Funny

Call of Duty®
Shared: Multiplayer · FPS · Singleplayer

Liars Bar
Shared: Multiplayer · Indie · Funny

Blood and Bacon
Shared: Multiplayer · Funny · FPS

How to Fish
Shared: Multiplayer · Indie · FPS

Stardew Valley
Shared: Multiplayer · Simulation · Indie

Granny Simulator
Shared: Multiplayer · Simulation · Indie