Stuff like "Finish Classic 9.0 for the first time" or "Finish All-Star on Hard without taking healing items" would probably be achievements instead of challenges. "Nothing Harder!" and "Truly All-Star" probably would be their . Then, there could be more general achievements like Shield Breaker, "Pop 50 shields", Staying Alive, "Successfully use Up Special to recover 500 times", Knock-Out Millenium, "Score 1000 KOs with any character", or stuff like that. Some devs are really creative with their Achievement names, other prefer making more self-explanatory names. Honestly I prefer the latter. I'd rather have a bland title than some cringy joke.
Anyway, I doubt Nintendo of all companies would make achievements like this, but here are some ideas for some really hardcore ones:
- Serious dedication: Get 1000 KOs with all fighters.
- Incredible dedication: Play 1.000.000 versus battles.
- Adrenaline Rush: Get 500KOs when your health is above 300% (No Sudden Death).
- Classic Master: Finish Classic with all characters in 9.0 without equipments or customs.
- All-Star Master: Finish All-Star with all characters on Hard without taking healing items.
- Out of the Park: Hit for 15.000 feet or more in Home-Run Contest.
I must admit the second one would only be interesting if we could find a way for it not to be exploited.