Air Duel

The player can choose between a fighter jet and a helicopter, shoot down enemies in the air and on the ground, collect power-ups, and defeat bosses to complete the levels. The game is different from most others in this genre because you can change aircraft at the beginning of each level. The fighter jet always shoots straight ahead; power-ups make the shots wider and stronger. The helicopter fires thinner and weaker shots, but turns in the direction it is moving (similar to Zero Gunner later on), giving it a long range; power-ups increase the strength of the shots as well as the number of bullets per shot (adding a small "spread effect" to the shot while moving). Both the fighter plane and the helicopter start with three bombs that destroy everything in their path, including enemy shots. These bombs are also unique compared to similar games in that they create a series of small horizontal explosions that can be "aligned" with the line running across the ground by pressing the left and right buttons (similar to the helicopter's shots). Additional bombs can be collected throughout the game. If you lose a life, your power and bomb count are reset to their initial values. Air Duel is a challenging game, and later levels can become nearly unplayable if you lose a single life.