So I'll begin with the list of feedback topics specifically requested.
In terms of playability, the projectiles move very fast and are small and not very visible. The game ended up being spam vs. spam, and it was kind of more luck than skill that kept you from just catching a cluster of them and being dead.
The controls feel fine. Very basic, responsive. I don't feel like I'm "flying" as much as scrolling, to be honest. There's no acceleration or easing, and the dragon does not change animation or point upward or downward in any way when you go upward or downward.
The art and animation need work. Yes, it's hard to draw and animate a good dragon, and credit where it's due, your wings are animated nicely. Unfortunately, the dragon itself wobbles all around within the movie clip, just making it look like it's shaking the entire time and throwing off the smooth feel of the flight.
The portrait art, by comparison, is bizarrely bad-looking, and the character conveys a very unpleasant personality (no doubt not helped by the obnoxious ironic-memeish way of speaking).
The text speed seemed fine for my reading ability, though I think you'd be better served by having it be advanced by the player, rather than the player having to keep up with the text. There's some relatively simple AS that can accomplish this.
If my microphone were still functional, I might volunteer for voice acting. If there is voice acting in this that I'm supposed to critique, I can't hear it.
I think to make a game that people will really enjoy you're going to need a lot more to it than sidescroll press space dodge projectile.