The presentation is nice and the dynamic feel of everything is great.
Is it hard? It's more so annoying - I feel like this sort of thing works better for the flappy bird sort of games, where you clearly see the movement and quickly get a feel for the amount of time it takes to keep your character flying.
Here, with the angle changing it often feels bit like you are not really in control - that would probably pass with time and getting the feel for the timing, etc. Together with this comes the question - do we want to invest some time to learn it - I think people crave rewards - I tried the online demo version where it looks like everything is unlocked - I think you could add some motivation by crating the impression of a tangible reward - each track unlocks the next, the areas could be called not just "park" or "desert", but, for example, Green forest cup - this instantly says there's a competition here and when you are done you might get some recognition (for example the classic bronze, silver, gold medals based on star total). Have a little medal on there to remind of the progress, etc.
So in general it feels quite good, but needs more "game" stuff for motivation, I think.