Thank you for feedback,
Now, there are less shields in level 1, more shields in level 2 and in level 3 every star is shielded and 20 seconds bonus.
I downloaded sounds from Freesound.org
https://freesound.org/people/mattwasser/sounds/58920/
https://freesound.org/people/stumpbutt/sounds/381770/
https://freesound.org/people/suntemple/sounds/253176/
https://freesound.org/people/astrand/sounds/328011/
https://freesound.org/people/stumpbutt/sounds/381778/
https://freesound.org/people/stumpbutt/sounds/381768/