I really want to beat this~~!!!

At first, it seemed manageable and it was... There weren't many ads, I thought... but after passing round 50... You can buy hearts with coins, but you have to watch an ad after each round to get coins... I initially thought I'd get coins without watching ads, so I kept playing without watching them, but no coins accumulated ㅜ... Now, I have to watch an ad after every clear... (You need 100 coins to buy a heart) When a round starts, you really need to check if it's turn-based or time-based... I thought it was all turn-based and failed due to time out ㅠ.. Some difficult rounds can take over 10 tries to clear... but they usually get cleared after a few more attempts... haha. For difficult rounds, if you think you can clear it in one or two more tries, use 50 coins to add turns then... Don't use them on easy rounds ㅡㅠ It's tough to save coins ㅜ... I want to beat it, but the hearts fill up so slowly, it's infuriating~~!!!!!!