As Switzerland maintained a strict neutrality policy, the Swiss government recognised the importance of maintaining well-equipped and self-sufficient armed forces to serve as a deterrent against potential incursions. One example of this is the EKW C-36, a domestic ground attack aircraft developed in 1935 by the state-owned arms manufacturer EKW to replace the Fokker C.V-E biplanes. Although the Swiss Air Force considered purchasing German Bf 110 or French Potez 63 attackers, a decision was made to proceed with the C-36 after bids for both aircraft failed. The first prototype, designated C-3601, made its maiden flight on 15 May 1939. It was further refined into the C-3603, the main serial production model that entered service in 1942, featuring retractable undercarriage and a single 20 mm Oerlikon autocannon mounted in the propeller hub. During World War II, the C-36s were deployed to repel trespassing aircraft to defend Swiss neutrality, though due to its low top speed, it was relegated to training and target-towing duties. In total, 175 C-36s of all variants were built, and would be fully retired from the Swiss Air Force in 1988.

The C-3604 was an upgraded variant of the C-3603. It featured a more powerful engine and two additional 20 mm Hispano-Suiza cannons in its wings to supplement the one mounted in the nose. In total, 13 C-3604s (including the prototype) were built.

Introduced in Update "Leviathans", the C-3604 is remarkably similar to the Soviet IL-2 series, featuring powerful offensive armaments, decent survivability, and a surprisingly good turn radius. The three Hispano autocannons are quite versatile, as they can be effectively used against both air and ground targets. However, the C-3604 has limited energy retention, top speed, climb rate, and mediocre defensive armaments, which can be easily exploited by opponents in bringing it down.