Pierre:
"The physics are WRONG. The "energy" (the height and speed) of a fireball shouldn't be twice as strong when you just-so-happen to hit some stone block "exactly on its corner", instead of one of its flat sides. This "bug" is actually one of tyhese games features because hitting "exactly on the corner" is required in order to "ace" several levels. This is very bad game design as it makes the game dependent on pinpointing exactly a specific *pixel*. If that is the behavior desired, then user input should have been two numbers instead of the mouse: shooting power (%) and shooting angle (degrees)."
Why are you reading my mind?