Damn. What an addictive and fun game! I really like the experience. I gotta say that the Tundra level is pretty brutal and I don't think I can beat it currently. My main feedback would be on the card type. Like mentioned, the water and air type are difficult to spot at glance and the booster vs attack card are too similar, so it would be nice to change the design slightly so that we can easily spot the difference between a boost card and an attack card.
Great to hear you liked it! I'll have a rethink on how to easily differentiate the types of cards and elements.
Tundra is definitely a challenging one. It took a fair few goes myself to beat it as you see in that 3rd screenshot but it's a fun stretch for this initial version.
Thanks a lot for the feedback