Games like Celestis
Games like Celestis include Bloons TD 6, The Escapists 2, Company of Heroes 3, Among Us, and Company of Heroes 2. We matched them by the tags players give Celestis on Steam (Strategy, Multiplayer, Singleplayer, 2D, and RTS): closest matches first, and among equally close ones the better-known games.

Bloons TD 6
Shared: Strategy · Multiplayer · Singleplayer

The Escapists 2
Shared: Strategy · Multiplayer · Co-op

Company of Heroes 3
Shared: Strategy · Singleplayer · Multiplayer

Among Us
Shared: Multiplayer · 2D · Co-op

Company of Heroes 2
Shared: Strategy · Multiplayer · RTS

Warhammer 40,000: Dawn of War - Definitive Edition
Shared: Strategy · Multiplayer · Singleplayer

Sins of a Solar Empire II
Shared: Strategy · Singleplayer · RTS

Plague Inc: Evolved
Shared: Strategy · Singleplayer · Multiplayer

Castle Crashers®
Shared: Co-op · 2D · Multiplayer

STAR WARS™ Empire at War - Gold Pack
Shared: Strategy · Multiplayer · RTS

Cosmoteer: Starship Architect & Commander
Shared: Singleplayer · Strategy · 2D

Overcooked! 2
Shared: Multiplayer · Co-op · Casual

ShellShock Live
Shared: Strategy · Multiplayer · 2D

Battlefleet Gothic: Armada 2
Shared: Strategy · RTS · Singleplayer

Planetary Annihilation: TITANS
Shared: Strategy · RTS · Multiplayer

Age of Empires II (Retired)
Shared: Strategy · Multiplayer · RTS

Rusted Warfare - RTS
Shared: Strategy · RTS · Multiplayer

Don't Starve Together
Shared: Multiplayer · Co-op · 2D

Age of Empires III: Definitive Edition
Shared: Strategy · Multiplayer · RTS

Liars Bar
Shared: Multiplayer · Co-op · PvP

Total War: WARHAMMER II
Shared: Strategy · RTS · Multiplayer

Homeworld 3
Shared: Strategy · RTS · Singleplayer

Gang Beasts
Shared: Multiplayer · Co-op · Singleplayer

Mindustry
Shared: Strategy · RTS · Multiplayer