Sky on Fire: 1940 places the player in aerial battles over Western Europe during the early stages of World War II. The aircraft represent the air forces of Britain, France, Germany, and Italy. Players operate fighters and bombers during military operations involving aerial combat and attacks on various targets. Enemy aircraft are controlled by AI, and battles can range from individual encounters to engagements involving multiple formations. Aircraft can also suffer damage that affects their performance during flight.

Missions and Historical Context

The setting includes events associated with the Battle of France and the Battle of Britain, but there is no continuous character-driven storyline. Gameplay is organized around individual flights with specific objectives rather than a linear sequence of story levels. One mission may require intercepting enemy bombers, while another involves attacking an airfield or a ship convoy. Players can also perform takeoff and landing exercises without participating in combat.

Aircraft and Available Activities

The game features aircraft with different functions, flight characteristics, and weapon configurations. Available models include the Spitfire, Hurricane, Bf 109, Bf 110, Ju 87, Ju 88, and He 111. Players can choose between several activities that determine the conditions and objectives of a flight:

•         Practice Flights: Perform takeoffs, landings, and basic aircraft maneuvers.
•         Aerial Battles: Fight AI-controlled opponents in individual dogfights or larger engagements.
•         Attack Missions: Intercept aircraft, strike airfields, and attack ships or ground targets.
•         Custom Scenarios: Use the mission editor to arrange aircraft and configure combat situations.

Some aircraft contain multiple crew positions that players can control individually. It is possible to switch from the pilot’s seat to a defensive gunner or bombardier position while the AI continues flying. Gunners operate weapons against approaching enemies, while bombardiers aim and release bombs over designated targets. The game also provides a free camera and photo mode for observing aircraft and capturing images during flights.

Flying and Completing Objectives

A session begins with selecting an aircraft and a flight scenario. Players then manage direction, altitude, and speed while navigating through the environment. During dogfights, maneuvering determines whether an enemy enters the firing line. Bombing tasks require approaching a designated location and releasing weapons over the target. Aircraft damage can affect the ability to continue an operation, requiring adjustments to flight behavior. After completing a sortie, players can select another aircraft or modify a custom scenario to experience different combat conditions.