All bonus
On the options screen, click up, down, down, left, left, right, right, select, start, select, start, square, circle, square, circle, x (2), start.
Invincible
Pause the game with Start, enter the control options, and enter below, X, Select, Start, right, square, left, circle, top, triangle.
All improvements
Pause the game with Start, go to the control options screen. There clicks below, X, Select, Start, Right, Square, Left, Circle, Up, Triangle