lack of music was a bit downer and because of silent background enemy death sounds became irrritating after a while. maybe it's just me but it felt kinda intuitive to be able to use coins for placing extra holes (same way you're able to use coins/mana to either place extra towers/or upgrade existing ones in other tower defence games) so took me a while to figure out that wasn't the case at the start. despite all, i had fun, good job.