Games like Fleets of Calder
Games like Fleets of Calder include Aliens: Dark Descent, Door Kickers 2: Task Force North, Door Kickers, Halo: Spartan Assault, and Reassembly. We matched them by the tags players give Fleets of Calder on Steam (Strategy, Top-Down Shooter, Real Time Tactics, Action, and Sandbox): closest matches first, and among equally close ones the better-known games.

Aliens: Dark Descent
Shared: Strategy · Action · Real Time Tactics

Door Kickers 2: Task Force North
Shared: Real Time Tactics · Strategy · Action

Door Kickers
Shared: Strategy · Action · Top-Down

Halo: Spartan Assault
Shared: Top-Down Shooter · Action · Strategy

Reassembly
Shared: Strategy · Sandbox · Action

RUNNING WITH RIFLES
Shared: Top-Down Shooter · Action · Sandbox

Heat Signature
Shared: Strategy · Action · Top-Down

Arma Reforger
Shared: Shooter · Strategy · Action

Freeman: Guerrilla Warfare
Shared: Strategy · Action · Shooter

Space Pirates and Zombies
Shared: Action · Strategy · Top-Down

Police Stories
Shared: Strategy · Action · Top-Down Shooter

FTL: Faster Than Light
Shared: Strategy · Space · Sci-fi

Star Valor
Shared: Action · Sandbox · Top-Down Shooter

X-Morph: Defense
Shared: Strategy · Action · Top-Down Shooter

HELLDIVERS™ Dive Harder Edition
Shared: Top-Down Shooter · Action · Shooter

Lumencraft
Shared: Strategy · Action · Sandbox

Stellaris
Shared: Strategy · Sandbox · Space

Arma 3
Shared: Action · Shooter · Strategy

Shadow Tactics: Blades of the Shogun
Shared: Strategy · Real Time Tactics · Action

Halo: Spartan Strike
Shared: Top-Down Shooter · Action · Strategy

Escape From Duckov
Shared: Action · Top-Down Shooter · Shooter

Ravenfield
Shared: Shooter · Sandbox · Action

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

PUBG: BATTLEGROUNDS
Shared: Shooter · Action · Strategy