Games like Summer Party Slaughter
Games like Summer Party Slaughter include Left 4 Dead 2, R.E.P.O., PAYDAY 2, Starship Troopers: Extermination, and GTFO. We matched them by the tags players give Summer Party Slaughter on Steam (Action, Horror, Multiplayer, Online Co-Op, and Casual): closest matches first, and among equally close ones the better-known games.

Left 4 Dead 2
Shared: Multiplayer · Action · FPS

R.E.P.O.
Shared: Horror · Multiplayer · Online Co-Op

PAYDAY 2
Shared: Action · Multiplayer · FPS

Starship Troopers: Extermination
Shared: Action · Online Co-Op · FPS

GTFO
Shared: Horror · Online Co-Op · Multiplayer

Escape the Backrooms
Shared: Horror · Multiplayer · Online Co-Op

Dead by Daylight
Shared: Horror · Multiplayer · Online Co-Op

Dying Light
Shared: Horror · Online Co-Op · Action

How to Fish
Shared: Multiplayer · Online Co-Op · Action

Back 4 Blood
Shared: Multiplayer · Online Co-Op · Action

MECCHA CHAMELEON
Shared: Multiplayer · Casual · Online Co-Op

Witch It
Shared: Multiplayer · Action · Casual

Phasmophobia
Shared: Horror · Multiplayer · Online Co-Op

Blood and Bacon
Shared: Multiplayer · Action · Horror

Liars Bar
Shared: Multiplayer · Casual · Online Co-Op

Left 4 Dead
Shared: Multiplayer · Action · Horror

PUBG: BATTLEGROUNDS
Shared: Multiplayer · Action · FPS

BIGFOOT
Shared: Horror · Multiplayer · Online Co-Op

The Outlast Trials
Shared: Horror · Multiplayer · Action

Pacify
Shared: Horror · Multiplayer · Online Co-Op

Killing Floor 2
Shared: Multiplayer · Online Co-Op · FPS

HELLDIVERS™ 2
Shared: Online Co-Op · Multiplayer · Action

Killing Floor
Shared: Horror · FPS · Action

PAYDAY 3
Shared: Action · Multiplayer · FPS