Games like DG2: Defense Grid 2
Games like DG2: Defense Grid 2 include Aliens: Dark Descent, Planetary Annihilation: TITANS, Taur, Warhammer 40,000: Dawn of War III, and STAR WARS™ Empire at War - Gold Pack. We matched them by the tags players give DG2: Defense Grid 2 on Steam (Tower Defense, Strategy, Action, Sci-fi, and Tactical): closest matches first, and among equally close ones the better-known games.

Aliens: Dark Descent
Shared: Strategy · Action · Tactical

Planetary Annihilation: TITANS
Shared: Strategy · RTS · Base Building

Taur
Shared: Tower Defense · Strategy · Action

Warhammer 40,000: Dawn of War III
Shared: Strategy · Sci-fi · Action

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

Mindustry
Shared: Tower Defense · Strategy · Base Building

Halo Wars: Definitive Edition
Shared: Strategy · Base Building · RTS

Infested Planet
Shared: Tower Defense · Strategy · Action

Warhammer 40,000: Dawn of War - Anniversary Edition (Classic)
Shared: Strategy · Sci-fi · Base Building

Thronefall
Shared: Tower Defense · Strategy · Action

Battlefleet Gothic: Armada (Classic)
Shared: Strategy · Sci-fi · RTS

XCOM: Enemy Unknown
Shared: Strategy · Tactical · Sci-fi

They Are Billions
Shared: Strategy · Base Building · Tower Defense

Sanctum 2
Shared: Tower Defense · Strategy · Action

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

Company of Heroes 2
Shared: Strategy · Tactical · RTS

Creeper World 4
Shared: Tower Defense · Strategy · RTS

Age of Darkness: Final Stand
Shared: Tower Defense · Strategy · RTS

X-Morph: Defense
Shared: Tower Defense · Strategy · Action

Warhammer 40,000: Dawn of War - Definitive Edition
Shared: Strategy · RTS · Base Building

Warhammer 40,000: Dawn of War II - Anniversary Edition (Classic)
Shared: Strategy · Sci-fi · RTS

Supreme Commander 2
Shared: Strategy · Sci-fi · RTS

Supreme Commander: Forged Alliance
Shared: Strategy · Sci-fi · RTS

Total War: WARHAMMER III
Shared: Strategy · RTS · Action