Games like Medieval Invasion
Games like Medieval Invasion include Bloons TD 6, Plants vs. Zombies GOTY Edition, Thronefall, Rogue Tower, and Emberward. We matched them by the tags players give Medieval Invasion on Steam (Strategy, Tower Defense, 3D, Cute, and Colorful): closest matches first, and among equally close ones the better-known games.

Bloons TD 6
Shared: Strategy · Tower Defense · Singleplayer

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

Thronefall
Shared: Strategy · Tower Defense · 3D

Rogue Tower
Shared: Strategy · Tower Defense · 3D

Emberward
Shared: Tower Defense · Strategy · 3D

Slime Rancher 2
Shared: Cute · Singleplayer · Colorful

Kingdom Rush Vengeance - Tower Defense
Shared: Strategy · Tower Defense · Singleplayer

Bloons TD 5
Shared: Strategy · Tower Defense · Singleplayer

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

Totally Accurate Battle Simulator
Shared: Strategy · Singleplayer · Colorful

Kingdom Rush Frontiers - Tower Defense
Shared: Strategy · Tower Defense · Singleplayer

Outpost: Infinity Siege
Shared: Tower Defense · 3D · Singleplayer

Slime Rancher
Shared: Cute · Singleplayer · Colorful

Bee Island
Shared: Strategy · Tower Defense · 3D

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

Orcs Must Die! 3
Shared: Tower Defense · Strategy · 3D

Tiny Tactics
Shared: Strategy · Tower Defense · 3D

The WereCleaner
Shared: Strategy · Cute · Singleplayer

Planet Coaster 2
Shared: Strategy · 3D · Singleplayer

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

Cluckmech Oasis
Shared: Strategy · Tower Defense · Cute

Kingdom Two Crowns
Shared: Tower Defense · Strategy · Singleplayer

Kunitsu-Gami: Path of the Goddess
Shared: Strategy · Tower Defense · 3D

MiSide
Shared: Cute · 3D · Singleplayer