Games like The Extinction Directive
Games like The Extinction Directive include Creeper World 4, Broken Arrow, Starship Troopers: Terran Command, Aliens: Dark Descent, and Wargame: Red Dragon. We matched them by the tags players give The Extinction Directive on Steam (Strategy, RTS, Tower Defense, Real Time Tactics, and Wargame): closest matches first, and among equally close ones the better-known games.

Creeper World 4
Shared: Tower Defense · Real Time Tactics · RTS

Broken Arrow
Shared: Strategy · RTS · Wargame

Starship Troopers: Terran Command
Shared: Strategy · RTS · Tactical

Aliens: Dark Descent
Shared: Strategy · RTS · Real Time Tactics

Wargame: Red Dragon
Shared: Strategy · RTS · Wargame

Company of Heroes 3
Shared: Strategy · RTS · Wargame

Bad North: Jotunn Edition
Shared: Wargame · Tower Defense · Real Time Tactics

WARNO
Shared: RTS · Strategy · Wargame

Total War: WARHAMMER III
Shared: Strategy · RTS · Real Time Tactics

Taur
Shared: Strategy · Tower Defense · RTS

Regiments
Shared: Strategy · Real Time Tactics · Wargame

Master of Command
Shared: Strategy · RTS · Real Time Tactics

Planetary Annihilation: TITANS
Shared: Strategy · RTS · Real Time Tactics

Ultimate General: Civil War
Shared: Real Time Tactics · Wargame · RTS

Kingdom Heroes 8
Shared: RTS · Real Time Tactics · Strategy

Total War: WARHAMMER II
Shared: Strategy · RTS · War

Infested Planet
Shared: Strategy · Tower Defense · RTS

Warpips
Shared: Strategy · RTS · Tower Defense

DG2: Defense Grid 2
Shared: Strategy · Tower Defense · RTS

Creeper World 3: Arc Eternal
Shared: Strategy · Tower Defense · RTS

Total War: THREE KINGDOMS
Shared: Strategy · RTS · War

Men of War: Assault Squad 2
Shared: Strategy · RTS · War

STAR WARS™ Empire at War - Gold Pack
Shared: Strategy · RTS · Sci-fi

Mechabellum
Shared: Strategy · Wargame · RTS