Games like Falcon 4.0
Games like Falcon 4.0 include Arma 3, War Thunder, VTOL VR, Arma Reforger, and Microsoft Flight Simulator X: Steam Edition. We matched them by the tags players give Falcon 4.0 on Steam (Simulation, Flight, Military, Realistic, and 1990's): closest matches first, and among equally close ones the better-known games.

Arma 3
Shared: Military · Simulation · Action

War Thunder
Shared: Simulation · Flight · Action

VTOL VR
Shared: Flight · Simulation · Military

Arma Reforger
Shared: Simulation · Military · Realistic

Microsoft Flight Simulator X: Steam Edition
Shared: Simulation · Flight · Realistic

Arma 2: Operation Arrowhead
Shared: Simulation · Military · Action

Nuclear Option
Shared: Simulation · Flight · Military

ACE COMBAT™ 7: SKIES UNKNOWN
Shared: Flight · Military · War

Project Wingman
Shared: Flight · Military · Action

Hell Let Loose
Shared: Realistic · Military · Singleplayer

Battlefield™ 6
Shared: Military · Action · Singleplayer

Microsoft Flight Simulator (2020) 40th Anniversary Edition
Shared: Simulation · Flight · Realistic

Hell Let Loose: Vietnam
Shared: Simulation · Action · Military

Totally Accurate Battle Simulator
Shared: Simulation · Realistic · War

FPV Kamikaze Drone
Shared: Simulation · Action · Flight

Mount & Blade II: Bannerlord
Shared: Strategy · War · Simulation

WARDOGS
Shared: Military · Action · Realistic

Men of War: Assault Squad 2
Shared: Simulation · Military · War

Squad 44
Shared: Simulation · Military · Realistic

IRON NEST: Heavy Turret Simulator
Shared: Simulation · Military · Realistic

UBOAT
Shared: Simulation · Military · Realistic

Squad
Shared: Military · Realistic · Action

IL-2 Sturmovik: Battle of Stalingrad
Shared: Simulation · Flight · Realistic

War of Rights
Shared: Realistic · Military · Simulation