Games like HexLab
Games like HexLab include Tabletop Simulator, Garry's Mod, Dorfromantik, BattleTech, and Rento Fortune: Online Dice Board Game (大富翁). We matched them by the tags players give HexLab on Steam (Turn-Based Tactics, Casual, Sandbox, Robots, and Physics): closest matches first, and among equally close ones the better-known games.

Tabletop Simulator
Shared: Sandbox · Board Game · Tabletop

Garry's Mod
Shared: Sandbox · Casual · Physics

Dorfromantik
Shared: Casual · Sandbox · Board Game

BattleTech
Shared: Turn-Based Tactics · Turn-Based · Robots

Rento Fortune: Online Dice Board Game (大富翁)
Shared: Casual · Board Game · Turn-Based Tactics

Totally Accurate Battle Simulator
Shared: Sandbox · Physics · PvP

Armello
Shared: PvP · Board Game · Turn-Based

Liars Bar
Shared: Casual · PvP · Indie

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

Richman 11
Shared: Casual · Turn-Based Tactics · PvP

Teardown
Shared: Sandbox · Physics · PvP

Your Only Move Is HUSTLE
Shared: Turn-Based Tactics · Sandbox · Turn-Based Strategy

Chess Ultra
Shared: Casual · Board Game · Tabletop

Richman10
Shared: Casual · Board Game · Tabletop

Yacht Dice
Shared: Casual · PvP · Turn-Based Tactics

Carcassonne - Tiles and Tactics
Shared: Casual · Board Game · Turn-Based

GoreBox
Shared: Sandbox · Physics · Casual

Warhammer Underworlds - Shadespire Edition (Classic)
Shared: Turn-Based Tactics · Casual · PvP

Age of History II
Shared: Sandbox · Turn-Based · Turn-Based Strategy

The Battle of Polytopia
Shared: Turn-Based Tactics · Turn-Based · Turn-Based Strategy

Noita
Shared: Physics · Sandbox · Difficult

100% Orange Juice
Shared: Casual · Board Game · Turn-Based

Besiege
Shared: Sandbox · Physics · PvP

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