Level skip:
Press [Run/Stop] to pause game play. Then, type one of the following codes according to the current level to advance to the next level. 

Current level Code 
1 MY NUTS ARE FROZEN  
2 OH MY SORE BUM  
3 BLOODY BEARS  
4 YUK SARDINES  
5 JDF RULES  
6 BART WAS HERE  
7 HI HOMER  
8 SOD IT