Games like ARK: Extinction - Expansion Pack
Games like ARK: Extinction - Expansion Pack include ARK: Survival Evolved, Terraria, Warframe, Human Fall Flat, and Left 4 Dead 2. We matched them by the tags players give ARK: Extinction - Expansion Pack on Steam (Downloadable Content): closest matches first, and among equally close ones the better-known games.

ARK: Survival Evolved
Shared: Co-op · Single-player · Multi-player

Terraria
Shared: Co-op · Single-player · Multi-player

Warframe
Shared: Co-op · Single-player · Multi-player

Human Fall Flat
Shared: Co-op · Single-player · Multi-player

Left 4 Dead 2
Shared: Co-op · Single-player · Multi-player

DRAGON BALL XENOVERSE 2
Shared: Co-op · Single-player · Multi-player

Warhammer 40,000: Space Marine 2
Shared: Co-op · Single-player · Multi-player

Borderlands 2
Shared: Co-op · Single-player · Multi-player

Remnant: From the Ashes
Shared: Co-op · Single-player · Multi-player

Monster Hunter: World
Shared: Co-op · Single-player · Multi-player

REMNANT II®
Shared: Co-op · Single-player · Multi-player

Palworld
Shared: Co-op · Single-player · Multi-player

PAYDAY 2
Shared: Co-op · Single-player · Multi-player

Gunfire Reborn
Shared: Co-op · Single-player · Multi-player

Orcs Must Die! 2
Shared: Co-op · Single-player · Multi-player

PEAK
Shared: Co-op · Single-player · Multi-player

Delta Force
Shared: Co-op · Single-player · Multi-player

Don't Starve Together
Shared: Co-op · Single-player · Multi-player

Aimlabs
Shared: Single-player · Multi-player · Action

War Thunder
Shared: Single-player · Multi-player · MMO

Grim Dawn
Shared: Co-op · Single-player · Multi-player

ORION: Prelude
Shared: Co-op · Single-player · Multi-player

Hero Siege
Shared: Co-op · Single-player · Multi-player

Sons Of The Forest
Shared: Co-op · Single-player · Multi-player