- It needs to be possible without glitches. Though you don't have to use the game mechanics, it needs to be possible to do.
- The difficulty can vary from finding the first easter egg ever in Adventure to... beating the Elite 4 with a Magikarp.
- Sometimes the game just hands you the goal, in Recettear, complete the item encyclopedia; complete the gallery in Wind Waker.
- Games can have multiple goals. So far, I've come up with two: create a "wonder" (something like a city or Laputa) in survival mode, and slaying both of the bosses in hardcore mode.
- Yes, I'll put this online somewhere when it's "done." I'm already putting it in an HTML file because the tables are useful for doing something like this.
- I'll take commonly known challenges, like the aforementioned 3 day challenge from Majora's Mask, or the Nuzlocke challenge.
So, any ideas?