I take it that while it's in the current (No. 35) test stage, there's no way to abandon an ongoing battle?

Yes, it's vs the Aboxalypse (and at about 10 damage per attack, with Aboxy having about 2,300 health left, I'm not really sure I want to attack a couple hundred more times).

You can forfeit, go to Statistics and then click "forfeit battle".

Oh thank you!

I thought I'd be stuck there until Revision No.36