The game also becomes very uneventful once all the spellcards have been exhausted. The concept though is quite fun, being a very big subversion of Touhou and Pong.
Thanks for the video. It helps a lot with tracking down the issue. I haven't found it yet, but I'll be sure to upload a fix once I do (and make spell cards more frequent). Sorry you ran into that, and that you for the kind words in spite of it!