Games like Fortification: tower defence
Games like Fortification: tower defence include Bloons TD 6, Kingdom Two Crowns, Rogue Tower, Thronefall, and Creeper World 4. We matched them by the tags players give Fortification: tower defence on Steam (Strategy, Tower Defense, Real Time Tactics, Minimalist, and Building): closest matches first, and among equally close ones the better-known games.

Bloons TD 6
Shared: Strategy · Tower Defense · Co-op

Kingdom Two Crowns
Shared: Tower Defense · Minimalist · Building

Rogue Tower
Shared: Strategy · Tower Defense · Minimalist

Thronefall
Shared: Strategy · Tower Defense · Minimalist

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

Bloons TD 5
Shared: Strategy · Tower Defense · Co-op

ISLANDERS
Shared: Strategy · Building · Minimalist

Bee Island
Shared: Strategy · Tower Defense · Minimalist

Mini Motorways
Shared: Strategy · Minimalist · Casual

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

Stronghold Crusader: Definitive Edition
Shared: Strategy · Real Time Tactics · Building

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

Orcs Must Die! 3
Shared: Tower Defense · Strategy · Co-op

Legion TD 2 - Multiplayer Tower Defense
Shared: Tower Defense · Strategy · Co-op

X-Morph: Defense
Shared: Strategy · Tower Defense · Co-op

Planetary Annihilation: TITANS
Shared: Strategy · Real Time Tactics · Building

Orcs Must Die! 2
Shared: Tower Defense · Strategy · Co-op

Castle Story
Shared: Strategy · Building · Tower Defense

Sanctum 2
Shared: Tower Defense · Strategy · Co-op

Mindustry
Shared: Tower Defense · Strategy · Building

Mini Metro
Shared: Strategy · Minimalist · Casual

Kingdom Rush Origins - Tower Defense
Shared: Strategy · Tower Defense · Building

Warstone TD
Shared: Strategy · Tower Defense · Co-op

Artisan TD
Shared: Strategy · Tower Defense · Building