Fireflys Deckbuilding Bullet Hell thing

Bullet-hell game with 30-second rounds. At the end of each round, you are given a choice of different cards to select, each making the game harder in some way. Some cards give score multipliers, but they increase the difficulty by more. Each run of the game is unique. Features 12 cards, each doing something different. This is my first game development project. Let me know what I did well, and, more importantly, what I did terribly badly.