Enter 'RAINBOW ARTS' for your name.  The screen should turn 
grey. 
To warp to any level, enter the following: 
Level number, XX, followed by four digits that when added 
together equal the level number, XX, and then the level number 
reversed. 
Examples: To play level 12, Enter -> 12 XX 3333 XX 21
          12 = Level number, XX, 3+3+3+3 =12 etc.
 
If you want to hear the tunes type 'COUNTRY' and a menu will appear. 
 
Another tip allows you to get to level 33 (1 level after the last!)
 
Here's How: Find the special hole on level 1.  It's surrounded 
            by 3 left pointing arrows.  Fall down the hole, and 
            press the left mouse button.  You are now warped to 
            level 33!