Here's the paragraph of hints, with the key words in bold:
Keeping this in mind, I'd like to begin by talking about our weird lives. Each stage can be so free, except when the clock is ticking and the debug process is so hard you just want to say "Owwww!" I'm not paid enough money for this abuse; 57695 dollars wouldn't even be enough. I'd rather just watch TRON.
To derive the codes, translate the key words into numbers using the letter/number associations on a telephone. Like this:
With that in mind, here is the complete list of cheat codes. Entering a cheat code (except for the last two) will permanently unlock its option on the Extra Options screen. The cheat will not be active by default. To actually use the cheat, go to the Extra Options screen and set its option to "Yes."
|57695||57695||Color Select||Allows you to change the gameplay colors (walls, player, background)|
|3825||?||Allow Profanity||Certain combinations of initials will no longer be "censored."|
|3733||free||Free Play||You may continue an unlimited number of times. Credits option will be ignored.|
|25625||clock||Infinite Time||You may take as much time as you need to finish each level.|
|78243||stage||Stage Select||You may select any of the 30 levels to begin play on. This works for user-created levels, too.|
|93473||weird||Reverse Controls||Left becomes Right, Up becomes Down, and vice versa... good luck!|
|33284||debug||Debug Mode||Ugly-Looking Debug Mode appears at game start. I used this for testing during development.|
|69999||Owwww||Maniac Mode||Nibbles2 will not wait 1/18th of a second before drawing the next frame. This makes gameplay impossible except on really slow machines.|
|8766||TRON||TRON Mode||The end of your snake will not be erased. This makes retracing your steps impossible. How far can you get?|
|23446||begin||Novice Mode||Upon crashing into a wall, you will have a few seconds to change direction before actually losing a life. Essentially, you can't die unless you trap yourself.|
|54837||lives||9 lives||The Lives option will now go up to 9.|
|66639||money||9 credits||The Credits option will now go up to 9. Note that Free Play makes this code pretty useless.|