Games like Treefender
Games like Treefender include Bloons TD 6, BONEWORKS, Hard Bullet, BONELAB, and Wobbly Life. We matched them by the tags players give Treefender on Steam (Action, Sandbox, Adventure, Tower Defense, and Casual): closest matches first, and among equally close ones the better-known games.

Bloons TD 6
Shared: Tower Defense · Strategy · Casual

BONEWORKS
Shared: VR · Action · Sandbox

Hard Bullet
Shared: VR · Action · Sandbox

BONELAB
Shared: VR · Sandbox · Action

Wobbly Life
Shared: Adventure · Sandbox · Action

Totally Accurate Battle Simulator
Shared: Sandbox · Strategy · Adventure

Ultimate Epic Battle Simulator 2
Shared: Sandbox · Action · Strategy

Thronefall
Shared: Tower Defense · Action · Strategy

The Riftbreaker
Shared: Tower Defense · Base Building · Sandbox

s&box
Shared: Sandbox · Action · Casual

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

Mount & Blade II: Bannerlord
Shared: Strategy · Sandbox · Action

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

Bloons TD 5
Shared: Tower Defense · Action · Strategy

Garry's Mod
Shared: Sandbox · Casual · Action

House Flipper
Shared: Sandbox · Casual · Action

PUBG: BATTLEGROUNDS
Shared: Action · Shooter · Adventure

Grand Theft Auto V Legacy
Shared: Action · Adventure · Shooter

HITMAN World of Assassination
Shared: VR · Action · Sandbox

Once Human
Shared: Action · Adventure · Base Building

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

Cultivation Tales
Shared: Sandbox · Action · Adventure

Rock 'N' Roll Defense
Shared: Action · Tower Defense · Adventure

ShellShock Live
Shared: Action · Strategy · Casual