This version 3.4.7 now has a battle mode (instructions included), which also includes battling with your friends on Steam!
Battle Mode:
In order to access the Battle Mode, you'll need to have at least 8 Rare cards, and at least 1 Wonder Rare card. The rest of the instructions can be found inside!
Known Issue (Soon to be Resolved):
Currently, the game will ask you if you want to use the classic art or new AI generated art, however the AI art is coming in a later update, it's just going to take some time to fine tune them manually.