ReferenceError: Cards is not defined, http://etg.dek.im/etgify.js, 1592, 39, ReferenceError: Cards is not defined
(http://i.imgur.com/eHutqx6.png)
Pressing "cancel" (lolwut?) oddly enough causes the game to go on. Well, sort of. I can still play and draw but the AI doesn't seem to do anything.
Also the endless has some serious trouble against stall decks with purify and magma (or stoneskin I guess). Once you sit at 500maxhp and couple hundred regen / turn it often can't kill you even after filling the board and the opposite is true as well more or less. I doubt even a deck filled with black cats, epidemics and plagues could chew down 2^32 hp in a reasonable timeframe.