Thanks for taking the time to play my games =)
Oh wow it really is the same gameplay but your friends game has way cooler style.
I actually agree about the speed of the box, i tried making it faster but i found myself having a lot of collision problems. The worst thing about Continuum Box is the way i implemented the movement it was a really hacky messy way, and thats why im honestly not that happy with it, i ended up rushing to publish it to learn about exporting/publishing and monetizing with admob. What kind of sounds are you talking about, i think every action has a sound, there is not much to do move, collect stars, hit the wall. Later levels introduce new mechanics that add new sounds.
Glad you enjoyed SPC. Flappy Math was more an experiment to test how much atention can a game get on the store based on "famous" keywords like Flappy, turns out, not that much.