Ah, yeah toward the end of the jam we lacked time to create instructions before or during the levels. On the Help Screen and project page we clarify that enemy pieces can be destroyed. There are two win conditions, destroying all pieces or scoring Bingo. We can definitely increase the tokens that spawn, but not too much, we don't want scoring Bingo to be too easy.
Thank you for your feedback, we've got a hot-fix coming when the voting ends that will address Bingo balancing and lack of in-game instruction.