Wow! What an ambitious and well made game for such a short time. Really impressive. Graphics are beautiful. Was initially gonna critique the short music loop, then it changed with progression and was super impressed there too. Game feel with the controls and bouncing was great.
Only critique I can give is that it is too easy to really capitalize on it's mechanics. After a bit, I stopped even reading the upgrade cards or looking at arena, just clicked the cards random and fired at a random enemy.
With more time to design actual challenges to overcome I could see this being a legit full game!