Games like Dead Above
Games like Dead Above include Kenshi, 7 Days to Die, Rust, Once Human, and Terraria. We matched them by the tags players give Dead Above on Steam (Top-Down Shooter, Real Time Tactics, Sandbox, Building, and Strategy): closest matches first, and among equally close ones the better-known games.

Kenshi
Shared: Sandbox · Survival · RPG

7 Days to Die
Shared: Survival · Building · Base Building

Rust
Shared: Survival · Building · Sandbox

Once Human
Shared: Survival · Building · Action

Terraria
Shared: Sandbox · Survival · Building

Space Engineers
Shared: Sandbox · Building · Survival

Project Zomboid
Shared: Survival · Sandbox · Building

Scrap Mechanic
Shared: Sandbox · Building · Survival

Oxygen Not Included
Shared: Building · Survival · Base Building

Conan Exiles Enhanced
Shared: Survival · Building · Sandbox

Factorio
Shared: Sandbox · Strategy · Base Building

ARK: Survival Ascended
Shared: Survival · Building · Sandbox

RimWorld
Shared: Sandbox · Strategy · Survival

ARK: Survival Evolved
Shared: Survival · Building · Sandbox

Garry's Mod
Shared: Sandbox · Building · Casual

Prison Architect
Shared: Sandbox · Building · Strategy

Raft
Shared: Survival · Building · Sandbox

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

Medieval Dynasty
Shared: Building · Survival · Sandbox

Valheim
Shared: Survival · Building · Base Building

Cultivation Tales
Shared: Sandbox · Building · Survival

The Riftbreaker
Shared: Survival · Base Building · Sandbox

Portal Knights
Shared: Sandbox · Building · RPG

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