Games like CrystalKeepers
Games like CrystalKeepers include Inkbound, Bloons TD 6, Mindustry, Rogue Tower, and The Scroll of Taiwu : Beyond The Dome. We matched them by the tags players give CrystalKeepers on Steam (Time Management, Tactical RPG, 3D Platformer, Roguelite, and Sandbox): closest matches first, and among equally close ones the better-known games.

Inkbound
Shared: Tactical RPG · Roguelite · PvE

Bloons TD 6
Shared: Tower Defense · Strategy · Sandbox

Mindustry
Shared: Tower Defense · Sandbox · RTS

Rogue Tower
Shared: Tower Defense · Roguelite · Strategy

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

Total War: WARHAMMER
Shared: RPG · Tactical RPG · Strategy

King Arthur: Knight's Tale
Shared: Tactical RPG · RPG · Roguelite

The King is Watching
Shared: Tower Defense · Roguelite · RTS

Kenshi
Shared: Sandbox · RPG · Strategy RPG

Gladiator Guild Manager
Shared: RPG · Tactical RPG · Roguelite

Touhou Monster TD ~ 幻想乡妖怪塔防
Shared: Tactical RPG · Tower Defense · RPG

Tower Dominion
Shared: Tower Defense · Roguelite · Strategy

Kingdom Heroes 8
Shared: Tactical RPG · RTS · Strategy RPG

Lessaria: Fantasy Kingdom Sim
Shared: RTS · Strategy · Tower Defense

鬼谷八荒 Tale of Immortal
Shared: Tactical RPG · Sandbox · RPG

SpellForce: Conquest of Eo
Shared: Tactical RPG · RPG · Strategy

The Last Spell
Shared: RPG · Tactical RPG · Strategy

The Banner Saga
Shared: Tactical RPG · Strategy RPG · RPG

Nordhold
Shared: Roguelite · Tower Defense · Strategy

The Riftbreaker
Shared: Tower Defense · Sandbox · Base Building

We Who Are About To Die
Shared: Roguelite · RPG · Strategy

Emberward
Shared: Tower Defense · Roguelite · Strategy

Sir, We Have an Orc Problem
Shared: Tower Defense · Roguelite · PvE

Mount & Blade: Warband
Shared: Sandbox · RPG · Strategy