I really, really like the idea!
The gameplay was nice and the amount of content is neat for such a short timespan. However it felt a bit too random, more like, if you're lucky to make until round x, you win the game. By always choosing the "easiest" path once you got lucky you're going to win. But balancing in 48h is absurd so it's completely understandable.
Visually it was easy to understand and the monsters were cool. UI could be a bit more fitting but it works.
I liked the song. The SFX felt a bit lacking though, would be neat to have all the card effects going bonkers at once on a monster!
Managed to finish the game on my third run, the only bug I found was the text showing I had only 1 card left upon entering a new portal. But it was more of a visual thing 'cause once I started quelling the cards would be counted correctly.
Overall a very nice entry, would like to see the idea expanded.