This game drew me in and I played it for quite a bit, which for me is always a clear sign that the game is doing something right!
I thought it was super excited when I unlocked a new letter, but I was a bit bummed out that I could only equip it as a constant, I think it would have been a nice way to add some difficulty scaling to the game if that letter joined the other letters by coming in randomly. Maybe it would make the player stronger, but also the gameplay harder?
Either way, still really enjoyed this game!