I like the one-button/one-click concept at the core here! Picking upgrades with one click is a clever UI/UX choice. I felt like I got a handle on the pros/cons of different choices as I played, but the one thing I wasn't sure about was the timing of the click on the bobber. Should I hold? Tap a bunch? Just once?
That being said, this is a nice concept and that little bit of visual feedback would help a bunch if you continue working on it. I had a good time--nice job!!