Games like The Protagonist: EX-1
Games like The Protagonist: EX-1 include XCOM®: Chimera Squad, XCOM: Enemy Unknown, STAR WARS Zero Company™, XCOM 2, and The Last Spell. We matched them by the tags players give The Protagonist: EX-1 on Steam (Strategy, Turn-Based, Tactical, Aliens, and Sci-fi): closest matches first, and among equally close ones the better-known games.

XCOM®: Chimera Squad
Shared: Strategy · Turn-Based · Turn-Based Strategy

XCOM: Enemy Unknown
Shared: Strategy · Tactical · Turn-Based

STAR WARS Zero Company™
Shared: Strategy · Sci-fi · Turn-Based Strategy

XCOM 2
Shared: Strategy · Tactical · Turn-Based Combat

The Last Spell
Shared: Strategy · Turn-Based Strategy · Tactical

Warhammer 40,000: Mechanicus
Shared: Strategy · Turn-Based · Sci-fi

BattleTech
Shared: Strategy · Turn-Based · Sci-fi

Jagged Alliance 3
Shared: Strategy · Tactical · Turn-Based Tactics

MENACE
Shared: Strategy · Tactical · Turn-Based Strategy

Battle Brothers
Shared: Strategy · Tactical · Turn-Based Strategy

Into the Breach
Shared: Strategy · Turn-Based Strategy · Turn-Based

Gears Tactics
Shared: Strategy · Turn-Based · Tactical

Fell Seal: Arbiter's Mark
Shared: Strategy · Turn-Based Tactics · Turn-Based Strategy

Xenonauts 2
Shared: Strategy · Tactical · Turn-Based Strategy

Sid Meier's Civilization®: Beyond Earth™
Shared: Strategy · Sci-fi · Turn-Based

Mutant Year Zero: Road to Eden
Shared: Strategy · Tactical · Turn-Based

Warhammer 40,000: Mechanicus II
Shared: Strategy · Tactical · Turn-Based Tactics

The Banner Saga 3
Shared: Strategy · Turn-Based Tactics · Turn-Based Strategy

Mordheim: City of the Damned
Shared: Tactical · Turn-Based · Strategy

Warhammer 40,000: Battlesector
Shared: Strategy · Tactical · Turn-Based Strategy

X-COM: UFO Defense
Shared: Strategy · Turn-Based · Aliens

Hard West
Shared: Strategy · Turn-Based Strategy · Turn-Based

Banner of the Maid
Shared: Strategy · Turn-Based Strategy · Turn-Based Tactics

Hard West 2
Shared: Strategy · Turn-Based Strategy · Turn-Based