I've run into a few small bumps on my way to playing the game. My email is a bit slow; it can take 5 minutes between a message being sent and my receiving it. As a result my habit when registering for a new site is to click the "send me a confirmation message", then go do something else and click the confirmation link in my email when I remember. In this case the lag was a few hours so so. And in that time, my link expired. Happily, I was able re-register, but it was a bit annoying to have to hang around and confirm my address in a timely manner. Recommended: extend expiration window to 24 or 48 hours. I was baffled for a bit when I tried to play, briefly saw a frame for Flash, then got a message telling me to upgrade. I concluded the problem was that I was using Firefox's "click to play" support, and that some Javascript didn't know what was going on and redirected me. The actual problem is that you require 11.5, and I am unable to get anything newer 11.2 because Adobe dropped support for Linux. On that note, you might want to detect Linux browsers and special case the message, "Sorry, we required Flash 11.5 or newer, and Adobe has dropped support for your platform. You can use Google Chrome on Linux." Kinda annoying that I need two accounts, one for the game, one for the forums. Integration would be nifty.
Do you have Pepper ? http://www.cardhunter.com/forum/threads/what-you-need-to-play-card-hunter.332/#post-18727 I know f4l died. iirc, pepper should work.