You made this in 12 hours, I am honestly surprised to see how much you improved. I'm really glad to know that you had fun making this, The game is simple and speaks for itself, The difficulty of the levels aren't consistent, but isn't a huge problem. Even though i tried beating the levels on the way you built them to be beaten, I found other ways of beating this, It would be a bit more challenging if you added some collectibles, but still a nice game. I am glad that I waited for the next game.

Honestly this game isn't that bad, the music is a bit annoying.
Next time try to make the gameplay more easy and let it get harder along the way if you're gonna make a sequel. The graphics are a bit lacking, but i like how some textures switch but it happens too fast to truly appreciate the effort. a different obstacle type wouldn't hurt either just make sure to introduce them properly. A simple score or a better distance counter would add depth in to the game. Seeing that this is your first game, and you understand it isn't good. but with some work and practise you can make it amazing. I wish you luck in game making adventures.