The prequel to 1942, like the other games in the 194x series, is a top down shooter set in WWII.
One or two players control a P-38 (for player 1) or a Mosquito (for player 2), shooting enemy airplanes and ships. As in the previous games, one button shoots the airplane's weapon (which is upgradeable by collecting power ups left by enemies) and the other makes the airplane loop, destroying everything on screen (or causing extra damage to bosses, fought at the end of each level). The regular ammo is infinite, while the upgraded weapons have limited ammo. When the weapon button is held down, a bar at the bottom of the screen is charged and a special shot can be released, which varies in effect from weapon to weapon.