I played this game before the most recent update, and I found it incredibly frustrating. I couldn't manage to win a singular run, partially due to actual losses, and partially due to the game crashing in my browser. It didn't feel *hard*, just unbalanced. From what I can see in this newest demo, that problem still seems to be around. I won my FIRST RUN of this update, with the help of some of the newly added cards. That made me feel like I wasn't really the one who'd won... it was simply that the cards got stronger, so the game got easier. That's not a good feeling.
I will say that the crashing seems to be fixed, which is great. However, I hope the balance is adjusted in the future.