Start the game with parameter "debug". ("arcanoid.exe debug").
Now, while playing, you can press "Backspace" to open command 
window. Here you can type any GameMaker's GML command.


Code                  Effect
----------------------------------------------------------------
room_goto(levelXX); - Level Select (Where XX is number from 1 to 50)
                      (ex. room_goto(level5); room_goto(level45); ) 
                      will let you enter any game level.
lives=99;           - will give you 99 lives.

PLEASE NOTE: In debug mode, you can send direct GML commands to the
game. Misspelling can cause game to hang up!