Simple but pretty good endless runner game. As mentioned in Iggy's comment, the difficulty increase needs some tweaking: I didn't even realize there was another level until checking the comment because it was going on for so long. You could try a gradual increase in difficulty as well, instead of having it level-based. Last thing is that the failure sound effect needs to be MUCH quieter, it's at least 4x as loud as the rest of the game which is very jarring.

Reminds me of the dinosaur game you can play in Google Chrome if you have no internet. My biggest problem with this is that it takes too long to get to the next level, so you go a long time without any escalation of difficulty. The music during gameplay is also too quiet. I do like the sprite work though.