Thanks for the complete review ! Yeah I was so focused on the plan i set up to be quick that I forgot something as basic as display the controls ^^;
I thought about it just a little after but my 3 hours were up so I believed in everyone and pray you would eventually found out what to do x)
For the middle notes, it's just that I needed to force the player going out of, well the middle, but again I didn't predict that it would go through the camera and I should have destroyed all the notes just after passing the player's z axis.
Thanks again, I'll make sure to explain the principles properly next time !