While in flight (or after you die) you can hit + s to go into slow mode.

You start out in the exact geographic centre of the island.

Now hit + x to turn on your joystick.

Now, you can move with your stick.

Here are the keys:

Hit 8 repeatedly to go forward

Hit 7 repeatedly to go up

Hit 6 repeatedly to go right

Hit 4 repeatedly to go left

Hit 2 repeatedly to go backwards

Hit 1 repeatedly to go down

The trigger fires the cannon and fires heavily toned down mavericks. Now you can visit the baseball field in Havanah, the hole in the wall, or complete the mission after you die.