So right off the bat I need to say I really find this concept engaging! I've played a ton of physical card/board games in my time and I'm really actually surprised that I haven't played something quite like this. After just two turns the concept really clicked with me and I was off! Ended up stacking Lumen Golems (My beloveds) and Alchemists to help fuel their production.
The card art, though simple, I actually quite enjoyed, each of the creatures have personality and are distinct enough that you can tell what they are by sight and don't need to do much hovering around reading them to strategize.
Since the player and their opponent play by slightly different rules when it comes to card positioning, it might be wise to delineate the front five spaces that the player can play cards in and the back ten that the opponent's cards move through. And just as well I do wish there was a way to either remove cards from my deck, or at the least, skip selecting new cards in-between rounds. This is because very quickly your deck becomes thick and somewhat unreliable. The only reason I believe that I lost was due to this, I ended up pulling several high cost cards in a row and could not play anything before it was too late in my last two duels.
Overall I really liked it! And I would absolutely play a more fully realized version of this, perhaps a little too much haha.