Air Duel
Air Duel is a vertically scrolling shooter game released for arcades by Irem in 1990. It was followed by an unofficial sequel called Air Assault in the west and Fire Barrel in Japan.
Gameplay
The player selects from a jet fighter or attack helicopter, shoot enemies in the air and ground, collect power-ups, and defeat bosses to advance levels.The game differs from most others in the genre in that the players can change the aircraft they use at the start of each level. The jet fighter always shoots straight forward; power-ups increase the width and strength of its shots. The helicopter fires thinner and weaker shots, but turns in the direction it moves, giving it great range; powerups increase the strength of shots, as well as the number of bullets per shot.
Both the fighter and the helicopter also start with three bombs which wipe out everything in their path, including enemy shots. These bombs are also unique compared to similar games, in that they produce a line of small horizontal blasts that can be "directed" at the line travels across the ground, by pressing left and right. Additional bombs can be picked up during the course of the game.
Losing a life resets the player's power and bomb count to the amount they start with. Later levels can become nearly unplayable if a single life is lost.