Games like Ultimus bellum
Games like Ultimus bellum include Plants vs. Zombies GOTY Edition, Bloons TD 6, Kingdom Rush - Tower Defense, Kingdom Rush Frontiers - Tower Defense, and The Scroll of Taiwu : Beyond The Dome. We matched them by the tags players give Ultimus bellum on Steam (Early Access, Indie, Strategy, RPG, and Tower Defense): closest matches first, and among equally close ones the better-known games.

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

Bloons TD 6
Shared: Strategy · Tower Defense · Singleplayer

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

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

The Scroll of Taiwu : Beyond The Dome
Shared: RPG · Strategy · Indie

Plague Inc: Evolved
Shared: Strategy · Indie · Singleplayer

Game Dev Tycoon
Shared: Indie · Strategy · Casual

Bloons TD 5
Shared: Strategy · Tower Defense · Casual

Overdungeon
Shared: Indie · Strategy · RPG

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

Melvor Idle
Shared: Indie · RPG · Casual

Undertale
Shared: RPG · Indie · Singleplayer

Slime Rancher
Shared: Singleplayer · Cute · Colorful

Orcs Must Die!
Shared: Strategy · Tower Defense · Indie

Prime World: Defenders
Shared: Indie · Strategy · Tower Defense

觅长生
Shared: RPG · Strategy · Indie

Mount & Blade II: Bannerlord
Shared: Strategy · RPG · Singleplayer

Chinese Parents
Shared: Indie · RPG · Casual

Sands of Salzaar
Shared: Strategy · RPG · Indie

GemCraft - Chasing Shadows
Shared: Indie · Strategy · Tower Defense

Swords and Souls: Neverseen
Shared: Indie · RPG · Singleplayer

Balatro
Shared: Strategy · Singleplayer · Indie

Rock 'N' Roll Defense
Shared: Strategy · Tower Defense · Casual

Orcs Must Die! 2
Shared: Tower Defense · Strategy · Indie