During the times of the NES, there were some strange things found in games. Some of these were just careless mistakes, others were obviously conjured by the sick minds of programmers. Screen shots and scans coming soon!
An interesting code indeed:
FUCKME with all the rest 1's
This will send you to the last area with next to nothing to defend yourself with.
At the end of the game, Congratulations is spelled "Congradulations"
Two things here:
1. If you look very carefully on Mike's skateboard on the cart label, it appears that "Sex" is written in spraypaint on it. It may be possible that it is the artist's signature (Rex).
2. The number of enemies you must defeat before you fight the boss in Level One just happens to be 69, take a look: