Games like Hex Defense
Games like Hex Defense include Arma Reforger, Arma 3, Men of War: Assault Squad 2, War Thunder, and Cities: Skylines. We matched them by the tags players give Hex Defense on Steam (Action, Casual, Strategy, Simulation, and Tower Defense): closest matches first, and among equally close ones the better-known games.

Arma Reforger
Shared: Simulation · Action · Strategy

Arma 3
Shared: Action · Simulation · Military

Men of War: Assault Squad 2
Shared: Strategy · Action · Simulation

War Thunder
Shared: Action · Simulation · VR

Cities: Skylines
Shared: Simulation · Strategy · Casual

Sea Power : Naval Combat in the Missile Age
Shared: Strategy · Simulation · Real Time Tactics

911 Operator
Shared: Strategy · Simulation · Casual

Hell Let Loose: Vietnam
Shared: Action · Strategy · Simulation

Bloons TD 6
Shared: Strategy · Tower Defense · Casual

Call to Arms
Shared: Strategy · Action · Simulation

Plague Inc: Evolved
Shared: Strategy · Simulation · Casual

Arma 2: Operation Arrowhead
Shared: Action · Simulation · Strategy

Bloons TD 5
Shared: Strategy · Action · Tower Defense

Starship Troopers: Terran Command
Shared: Strategy · Military · Sci-fi

Kingdom Rush - Tower Defense
Shared: Strategy · Tower Defense · Casual

Game Dev Tycoon
Shared: Simulation · Strategy · Casual

Plants vs. Zombies GOTY Edition
Shared: Strategy · Casual · Tower Defense

Call to Arms - Gates of Hell: Ostfront
Shared: Strategy · Real Time Tactics · Action

Toy Soldiers
Shared: Action · Strategy · Casual

VTOL VR
Shared: VR · Simulation · Action

Onward
Shared: VR · Action · Simulation

Wargame: Red Dragon
Shared: Strategy · Military · Simulation

Total Tank Simulator
Shared: Action · Strategy · Simulation

Mini Motorways
Shared: Strategy · Casual · Simulation