I have done a few runs through Class Challenge mode. The following video contains my current best (54:04).

I really like the idea. It would probably make it less luck dependant since you don't have to finish every game ridiculously fast to get a good time. The other thing is that you could do it without having all the cards needed for decent decks.

Yeah that's pretty cool, I'll add the category. Not sure about the name though, I thought it would just be Class Challenges Any% Normal or Normal%. I'll have to rename the other categories while I'm at it

EDIT: OK renamed the categories to be just what the game calls them in the menu (Normal, Class Challenges and Heroic) and I removed the "Any%" or "Normal%" parts since there is no alternate %, and I added your run to Class Challenges... Now we just need a Heroic run :D

Wow, thanks for adding it already. It will indeed be interesting to see who the first brave soul is to attempt a Heroic run. I can't even imagine such levels of frustration.