Show HN: I wrote a short story about the Minus World in Super Mario Bros

f52.charlieharrington.com

4 points·whatrocks··3 comments

Writing an NES game for my senior project helped me understand what exactly the minus 1 world was.

My Game had 4 levels, and if you go to the exit of the 4th level, you enter the secret, 5th level. Except it’s not a secret 5th level. It’s the answer to the question “what happens when you try to go to the next level and there is no next level?” It turns out you get a level built out of whatever is written in the ROM address.

Interesting - how come the Minus World is always a water level then? Could you figure out how to "create" a different Minus World somehow?

Also - it's definitely a one-day goal of mine to write an NES (or probably Game Boy emulator). That's a very cool senior project you had!

I don't know the exact answer to this, but the minus world is always the _same_ level data, even if that level data is invalid. The same was the case in my game, the "5th level" was weird garbage, but it was always the same weird garbage.

I suspect because SMB was a better architected game than what I wrote, the unpacking of the level data is substantially more reliable. There's a very interesting video that shows what you get if you keep incrementing the current-level byte, though I doubt there's a way to do it in game like you can with world -1

https://www.youtube.com/watch?v=riaf2vwMzMo

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