Makes sense! Shaders'll get you. UI is just hard. I *do* kind of like the golf-club cards in the posted screenshot, but I can see why, as you say, they might have had to go for space. I understand this game has to play on phones, too, and I've been playing it on a laptop.
I wouldn't say that your presentation of the challenge levels was drastically off or anything. Even something like a little floating "Optional Challenge Levels:" text hanging over them might have been enough to eliminate any confusion, at least for me.
Lots of the presentation is really good! Again, I don't know if I said this, but I love how thematic water and sand traps and bank shots are. Those are the most 'interpreting golf as puzzle mechanics' elements, and they really make the whole experience.
Oh. It might be interesting to note that I did encounter a level now that almost stumped me: 5-4. I admit I came close to giving up! It took me forever to realize what I could do with that chip2-roll2. Required a bit of lateral thinking. But I did get there.