Generally not bad, including the fact that I mostly hate flappy games. The only... awkward thing is the inconsistent "height" of a flap. Sometimes you are bouncing sky-high (especially annoying with the first ship) and sometimes you get a "micro-flap" and the changing position of the asteroids can put you in a position when you got almost no chance of avoiding the next ones if you know what I mean, especially when the lower asteroid is in the middle of the screen.
PS
And getting that 1000 points with the last ship is just a matter of pure luck because of the physics of the game. The ship is simply too big and the distances between subsequent pairs of asteroids so small that there is basically no room and time for any maneuverability.
PS for PS
I actually did it, but the medal is not working.
PS FOR ALL COMPLAINING THAT THE GAME IS NOT WORKING:
The game DOES work, both on Firefox and Chrome, just entered it twice. The only thing you need to do is to NOT change the tab when the game is loading, because otherwise the game cursor won't move.
For the future: check all the possibilities before zero-bombing with so much ease.