That's also an important point - based on whether the game is in portrait mode (phones) or landscape (PC / tablets / consoles) we switch up the card orientation from vertical to horizontal in order to make them more legible, and the design had to account for that :)
Yeah, putting a label saying "bonus" on top of the challenge levels might've helped - at the time I was determined to put in as little text as I could (both for localization reasons, as well as making the game more approachable to young kids) but that probably wouldn't have hurt as much.
Thanks! We tried to make the mechanics easily understandable at a glance even for golf newbies like us :)
I'll agree that 5-4 is a bit of a difficulty spike, and we probably should've made the puzzle a bit easier in hindsight.