Thanks for your feedback and taking the time to play!
This game isn't really aimed to be played with trackpad due to its nature, I tested the game with my own trackpad (as I work with a laptop) and it made the game unnecesarily so much harder that I decided against implementing anything. That's why there are no alternate controls (plus lack of time to think about any and implement it).
To encourage juggling with the mouse pointer, after a ball bounces 5 times on the platform it starts subtracting points instead of adding. This is explained on screen when you have just one ball on screen and falls down the lower limit. Did you have that screen show up? I think there could be a bug where it's not showing to some people.