How to play River Striker on Mac

You control a fighter jet in a top-down view over a river and get points for shooting down enemy helicopters, ships, planes, towers and airships. you refuel your fighter jet by flying over fuel-stations. You can shift side to side and change the speed of the plane using the innovative touch sensitive joystick. Watch out for the sea mines scattered around the river. Also shoot the towers (on the land) for bonus points. But remember, to go undetected, you must stay away from the land. So always fly over the river. When the end of a level is reached for the first time, the next level will be unlocked. A simple yet brilliant game. Are you good enough to overcome all obstacles and clear out the rivers from the enemy presence?