The dinosaur game was my first thought. It's quite similar yet different.
– Mostly consistent, appealing visuals. But try to keep consistent pixel size – the world has large pixels, the up arrow has smaller, and the score has the smallest. That doesn't look good; a pixel in a pixel art game should have the same size everywhere.
– Awesome accompanying music
– There is no immediate visual response to pressing the right arrow to speed up, so you initially have no idea if it even did anything. It could do some speed-up effect as a response.
– Since you can slide infinitely, the birds don't pose much danger. You don't care how high they fly, you can boil the game down to “keep sliding all the time and jump over rocks”.
– Sometimes I encountered obstacle combos that seemed impossible (a bird between two rocks close together), but perhaps it just needed a very precise timing.
– The score doesn't grow at a rate that feels good; you can run at lightning speed and the number increase doesn't seem to match your “speed thrill” very well
– This in no way belongs under the “Visual Novel” genre
– It would be nice to track your high score; it would give you more reason to play for longer
– The hitboxes aren't all that precise, sometimes you get a game over showing you not touching anything, just because the invisible colliders larger than the sprites grazed each other. But well, it's a pixel-art game, inaccurate colliders are more or less a staple of retro games.
It's a cool little game that remains enjoyable for a good while; well done.