How did "NO MORE PLAYERS" do that? I think it's hacking, after all you can be on the leaderboard multiple times, yet there is no progression between the previous records and their score.
Can you make the description of the items on the cards show when you hover on them in the deck builder? This is just quality of life, but it would help quite a bit.
Notes coming from below are very hard to prepare for sometimes. It's hard but really fun. As another suggestion, for the levels can it be clearer how long until we win? The scratches as platforms create an interesting dilemma.