I've found two things in the quick draw game (at least for kana, I haven't gotten farther yet).
First is in the mode where it shows characters with a countdown and then they disappear and you can write - if I pause while the character is still there and then unpause again, the countdown will disappear. The character is still there and I can't draw, but the time is running. And then I get hit and die ;)
The second might be a bug or might be intended? I'm not sure. Sometimes when I draw wrong it will tell me it's wrong and make me draw the line again - but sometimes it just says my writing is ugly but accept it as correct anyway, regardless of what I do. It will even count a dot in the corner as correct, even on the strictest difficulty. It does give me the circle instead of the flower though.
It's not really a problem, just something I noticed :)
The first issue does sound like a bug. I'm on vacation at the moment, but I will try to look into this soon.
As to the second, could you perhaps send me a video of the issue happening? The easiest way to send me the video is probably via email: you can send it to michael@renshuu.org.