Cheats:

 In the retail version:

 At the title screen type: GUBBLEDCHEAT and you will hear Gubble D.
 Gleep laugh, verifying that you entered the code correctly.

 Now you can try the following:

 From anywhere in a map, you can press:

 [F3] --> Removes all blocks from the map
 [F9] --> Advances you to the next city map

 From a launch pad on a map, you can press:

 [PageUp]   --> Advances to the next level
 [PageDown] --> Goes back to the previous level
 [Home]     --> Advances 10 levels
 [PageDown] --> Goes back 10 levels

 During play, you can press:

 [F8] --> Makes you Invincible! (Press F8 again to turn off
          invincibility)
 [F9] --> Completes any level
 [+]  --> Speeds you up
 [-]  --> Slows you down

 For the demo:

 Type GUBBLE at the title screen, you will hear Gubble D. Gleep laugh,
 verifying that you entered the code correctly.

 Now you can try the following:

 From the map:

 [F3] --> Removes all blocks from the maps
 [F9] --> Switches you between maps

 During play:

 [F8] --> Makes you Invincible! (Demo Version 1.1 only)
 [F9] --> Completes any level
 [+]  --> Speeds you up
 [-]  --> Slows you down