(I own this on Steam, but I figured messaging here might be more useful for you.)
My 4-year-old loves this game, but the controls feel very unnatural and in some cases counterintuitive. Maybe I've missed a setting, but at minimum I need to have some contextual control hints always visible.
Getting into and out of modes is very uncomfortable.
I really hate the right-click = undo control -- I constantly am deleting things without meaning to or realizing it. I don't mind it when I'm in "adding track" mode, but when I'm no longer in that mode, I would much rather be able to select objects and do things to them (including delete, but also move, rotate, etc).
CAN you modify existing objects? If so, I haven't been able to figure out how.
The controls aren't quite as awkward on a controller, but but on PC I've gone back and forth between the object select menu and the cancelling (with right-click) SO many times, and it makes me motion sick just remembering it.
I really wish I could play this with my son, but after about 5 or 10 minutes I have to sit down quietly in the dark for like an hour before my head starts feeling normal again. :(
I used be a mobile game designer, so if you'd like a more "formal" proposal from me, or want to ask me for more clarification or something, I'm happy to do what I can. I'm sure you're put a lot of time and effort INTO the controls (and I saw where you worked with a parent to help their child be able to use the game better, which is awesome!), so I hate yucking on them, but I just really can't play your game even though I REALLY REALLY want to.