Games like Orcdom
Games like Orcdom include Mindustry, Minimalist Tower Defense, Bloons TD 6, Oxygen Not Included, and Factorio. We matched them by the tags players give Orcdom on Steam (Tower Defense, Strategy, Real Time Tactics, Resource Management, and Pixel Graphics): closest matches first, and among equally close ones the better-known games.

Mindustry
Shared: Tower Defense · Resource Management · Strategy

Minimalist Tower Defense
Shared: Tower Defense · Strategy · Real Time Tactics

Bloons TD 6
Shared: Tower Defense · Strategy · Singleplayer

Oxygen Not Included
Shared: Resource Management · Base Building · Strategy

Factorio
Shared: Resource Management · Strategy · Base Building

Kingdom Rush Frontiers - Tower Defense
Shared: Tower Defense · Strategy · 2D

Plants vs. Zombies GOTY Edition
Shared: Tower Defense · Strategy · 2D

Dungeon Warfare
Shared: Tower Defense · Strategy · Pixel Graphics

Kingdom Rush Origins - Tower Defense
Shared: Tower Defense · Strategy · 2D

Kingdom Rush 5: Alliance TD
Shared: Tower Defense · Strategy · 2D

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

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

The King is Watching
Shared: Tower Defense · Strategy · Base Building

Prison Architect
Shared: Strategy · Base Building · Building

Stronghold: Definitive Edition
Shared: Strategy · Real Time Tactics · Tower Defense

Kingdom Rush - Tower Defense
Shared: Tower Defense · Strategy · 2D

Rise to Ruins
Shared: Tower Defense · Strategy · Pixel Graphics

Stronghold Crusader: Definitive Edition
Shared: Strategy · Real Time Tactics · Tower Defense

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

Kingdom Two Crowns
Shared: Tower Defense · Strategy · Base Building

Warpips
Shared: Tower Defense · Strategy · Resource Management

Sheltered
Shared: Strategy · Pixel Graphics · Base Building

Tower Dominion
Shared: Tower Defense · Strategy · Base Building

Tower Wizard
Shared: Strategy · Resource Management · Pixel Graphics