Ok, I've been playing this again and il drop some thoughts in here, I know you appreciate the feedback looneybits. :)
Lanes: It is kind of difficult to realise the separate lanes to begin with unless you been playing a few times.
Suggestion: You have 3 darker trials on the run path, maybe change this to 5 to show the player they are like lanes. After a period of time you could have these lighten/disappear as the waves/game gets harder. Or perhaps the speed effect you have could be rendered in a way they shows the lanes in a subtle manner nearer the zebra playing area.
"That's the deal, if you don't survive you won't get the stars."
I understand that, but i find that this really punishes the player. What i think will be a good idea would be to add another variable that gives the player something else to play for as well, maybe an XP, which could unlock things like a 'Jump' ,'invincibility' or 'continue' perk for a short while to give the player some hope of reaching the end of the waves. On many occasions i got to wave 4 after like 10 attempts only for the tree to kill me, (and i wasn't convinced i actually hit the tree) and lost all my coins on that run. Then to be honest i didn't feel like playing it anymore, had i got something for my trouble it would make it more the while playing or continue trying and not feel so hard done by.
i did notice that it does get slightly faster on some waves.
Hope this is helpful. :)