I stumbled this, and as much as I hate stumbling kana related stuff while stumbling "Japan" I decided to give it a try.
I picked hiragana with everything, First "character" I got was a tenten without any hiragana below it. I got 92/102, which included 1 tenten without character, 1 empty circle, 7 boxes (like the ones you get when you don't have Japanese installed) and 1 misstype. I was hoping it would give me some sort of summary at the end so I'll be able to tell you exactly which characters gave me these troubles, but since I didn't follow up myself and it didn't show I guess I can't do such thing.
It's definitely a good start, but it's a long way from being decent.
And I say that as someone who really hates kana "learning" games and think they're a waste of time.