To skip to the construction level, enter the password CBOBUNAABAASY65X.

Level                  Password
Back alley             MOOMIN 
Back street            MOONPIG  
Back street B          MOONPINGEON  
Back roof              SNUFFKIN  
Main street            LITTLE_MI  
Main street B          LITTLE_MO  
Vinnie's scrap yard    SOUP_DRAGON  
Vinnie's scrap yard B  SUPER_DRAGON  

Been in Beer's Bar? Having trouble in the Backstreets? Losing many precious lives.

When your in Beer's Bar punchout all the normal thugs but leave the red mouse. Jump up on stage get the posters and walk towards the far wall on the stage.Walk up and down there a bit until you get a life. Now jump down off the stage and walk to the top right corner of the bar. Punch the dog standing there. By doing this you can now go back onto the main street instead of going into the back streets.

TIP: Always check in places you can't see. There's always a life or some other goods hidden in dark corners.