Thanks for playing it for so long! I think if I managed to add more polish more people would enjoy it for longer. And yes, after playtesting it myself (after the jam was over unfortunately), I definitely agree that the player should have more control over the numbers on the board, but I was thinking more along the lines of giving the player powerups and abilities to swap numbers/remove cells/etc. as the game went on. Your idea of new numbers being guaranteed to exist on the board might not be effective though, because every time you destroy a number the numbers above it fall and that may make some numbers no longer pickable on the board.