haha lvl 12 was the hardest for me! 13 was pretty though too! and 14, but once you know how to beat these lvls it's not too hard anymore! (try the green cells first or some neutral cells).
Please make a sequel!
When I played normal mode (got to 25k for the card) but then I chatted a bit to let me die, and then the game got stuck I couldn't do anything, it kept saying Tap up arrow. I clicked in the game everywhere, I tapped up , I typed the letters... Nothing happened