FYI - To the left of the volleyball will be a tennis ball. Like you say, "you can't go back" but I'm certain it's within the first 200 holes. (I had to reinstall and restart on a new phone, so I'm feeling sure about that.) Spend some quality time cruising through the first 200 holes with binoculars.
Comment found on Mini Golf 100 +: To find treasure boxes , ...
I went through level by level like this and found all but one. It’s driving me crazy. I’m on level 300 and I’m just missing the one to the left of the volleyball. Did I write the hole numbers down when I found the others? Nope. Totally forgot. And, of course, they disappear once you open them so you can’t go back after the fact.
Comment found on Mini Golf 100 +: To find treasure boxes , ...