Games like Defence to death
Games like Defence to death include They Are Billions, Plants vs. Zombies GOTY Edition, Kingdom Two Crowns, This War of Mine, and Creeper World 3: Arc Eternal. We matched them by the tags players give Defence to death on Steam (Turn-Based Tactics, Strategy, Tower Defense, Singleplayer, and Atmospheric): closest matches first, and among equally close ones the better-known games.

They Are Billions
Shared: Strategy · Tower Defense · Zombies

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

Kingdom Two Crowns
Shared: Tower Defense · Singleplayer · Strategy

This War of Mine
Shared: Strategy · Singleplayer · Atmospheric

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

Bloons TD 6
Shared: Strategy · Tower Defense · Singleplayer

Frostpunk
Shared: Strategy · Survival · Singleplayer

Grim Nights
Shared: Strategy · Tower Defense · Survival

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

Plague Inc: Evolved
Shared: Strategy · Singleplayer · Zombies

Infection Free Zone
Shared: Strategy · Zombies · Survival

RimWorld
Shared: Strategy · Singleplayer · Survival

Mindustry
Shared: Tower Defense · Strategy · RTS

Oxygen Not Included
Shared: Singleplayer · Survival · Strategy

Dungeon Defenders
Shared: Tower Defense · Strategy · Singleplayer

Kingdom: New Lands
Shared: Tower Defense · Strategy · Survival

Castle Story
Shared: Strategy · Tower Defense · Singleplayer

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

From Glory To Goo
Shared: Strategy · Tower Defense · Real-Time with Pause

Infested Planet
Shared: Strategy · Tower Defense · Singleplayer

Taur
Shared: Strategy · Tower Defense · Singleplayer

Kingdom Rush 5: Alliance TD
Shared: Strategy · Tower Defense · Singleplayer

The Riftbreaker
Shared: Tower Defense · Survival · Singleplayer

FTL: Faster Than Light
Shared: Strategy · Singleplayer · Real-Time with Pause