There are several differences between Twin Hawk and its Japanese version "Dai Sen Puu
Twin Hawk supports two simultaneous players.
Dai Sen Puu supports two players, but only one at a time. Because of this, it also supports Cocktail cabinets.
In Twin Hawk, both planes are purple and pink for player 1 and 2 respectively.
In Dai Sen Puu, the planes are green for both players.
In Twin Hawk, when you die, you continue the game at current position.
In Dai Sen Puu, when you die, you continue the game at predefined positions. This makes the game much more difficult to complete.