Games like Battle for the Kingdom
Games like Battle for the Kingdom include Mount & Blade II: Bannerlord, Reigns, Across the Obelisk, SMITE 2, and Mount & Blade: Warband. We matched them by the tags players give Battle for the Kingdom on Steam (Casual, Strategy, Adventure, Early Access, and Medieval): closest matches first, and among equally close ones the better-known games.

Mount & Blade II: Bannerlord
Shared: Strategy · Medieval · Adventure

Reigns
Shared: Medieval · Card Game · Adventure

Across the Obelisk
Shared: Casual · Adventure · Card Game

SMITE 2
Shared: Strategy · Adventure · Casual

Mount & Blade: Warband
Shared: Strategy · Medieval · Adventure

Plebby Quest: The Crusades
Shared: Casual · Strategy · Adventure

Kingdom Rush - Tower Defense
Shared: Strategy · Casual · Adventure

UNO
Shared: Casual · Card Game · Strategy

Balatro
Shared: Card Game · Strategy · Casual

Choice of Life: Middle Ages 2
Shared: Adventure · Strategy · Casual

Slay the Spire 2
Shared: Strategy · Card Game · Early Access

Kingdom Rush Origins - Tower Defense
Shared: Strategy · Casual · Medieval

Choice of Life: Middle Ages
Shared: Strategy · Card Game · Medieval

Overdungeon
Shared: Strategy · Casual · Adventure

Plants vs. Zombies GOTY Edition
Shared: Strategy · Casual · Adventure

The Scroll of Taiwu : Beyond The Dome
Shared: Strategy · Adventure · Casual

Sultan's Game
Shared: Strategy · Adventure · Card Game

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

The Legend of Bum-Bo
Shared: Strategy · Adventure · Casual

亦春秋 Power Of Seasons
Shared: Adventure · Strategy · Casual

Demonic Mahjong
Shared: Strategy · Casual · Card Game

Notes of Soul
Shared: Adventure · Strategy · Casual

Death Coming/死神来了
Shared: Casual · Strategy · Adventure

ShellShock Live
Shared: Strategy · Casual · Early Access