Hmm I see what you're saying, but when I try it using the Cocoon JS app I get 60 fps constantly and those problems disappear, in fact I noticed that bug of the ball disappearing only happens when there's fps flutuation. So, I guess I'm gonna stick to time delta.
Great concept, I found it fun! Excellent use of one button gameplay.
Ohh thank you so much! That means a lot!
PS: How is your game going? I saw it some time ago and I remember it looked really interesting!