All-Star achievement glitch/bug?

[Shrewstur]

I currently have 6 challenges left to complete, in which I plan on using the 5 hammers to use on all of them except one. One of these challenges is what should be the among the easiest... "Clear All-Star With 10 characters." The "Clear All-Star with all characters" is also uncompleted. A friend of mine told me that beating All-Star in co-op would count. So I would either team up with that friend or with my sister, in hopes of completing these sooner.

I was able to get the achievements along the lines of collecting all final smash trophies or collecting trophies for all characters. I currently have 12 characters defeated in All-Star single player mode, wondering why I haven't gotten it, even when doing it just in single player.

One possibility I've thought of was that... I might have defeat All-Star for the first time on single player (1 time), then defeated it in co-op mode 5 times (11 times beaten total), so it might have skipped over.

Might I be forgetting anything? Any thoughts?

 

[Beninator]

It doesn't count when you do co-op, but you have cleared All Star with 12 different characters in single player?

I'd recommend trying to beat All Star (on single player) with more characters, and see if you get the achievements for 20 characters and so on.

And don't use hammers

 

[Shrewstur]

Perhaps... trying up until 20 might be worth a shot.

I don't think I have the skills nor determination to complete everything hammerless. o___o;;