1943 is the sequel to Capcom's highly successful vertical scrolling shooter 1942. The game takes place in the Pacific Theater of WWII during the Battle of Midway (as per the title) where the United States won a decisive victory over the Japanese navy. The game takes a few liberties with history and pits the player as a lone fighter pilot winning the battle on their own, and shooting down a lot more than four Japanese aircraft carriers.
The game consists of 16 levels through which the player must destroy waves of enemies to take on a large battleship, bomber boss, or fighter launching aircraft at the level's conclusion. The player, as in the previous game, pilots a Lockheed P-38 Lightning. The only major gameplay difference from 1942 is that the player is only given one life and rechargeable energy meter.
Shooting down groups of red enemy craft or touching animal icons hidden in the clouds will grant power-ups to the plane's abilities. Such power-ups include automatic guns, artillery shells, a shotgun blast, and even an anachronistically placed laser. The famous Capcom Yashichi symbol will restore health and the plane icon will grant two wingmen who attach to the wingtips and double the plane's firepower.
Players can also make use of a "bomb" ability that clears the screen of foes and bullets. This is context-sensitive to the part of a level the player is in, as it calls lightning while in the skies and a tidal wave if the plane is closer to the ocean. The bomb ability is to be used sparingly as it drains health with each use.
The NES version of the game introduced the ability to upgrade the P-38 throughout the course of the game and featured 24 levels instead of 16.