This is neat good-ol' infinite runner! My highest score was 101.
To give you some feedback, in all my attempts I didn't even come close to using 20 seconds, since the obstacles took me out long before then. Instead of changing them, I wonder if you could add a bunch of easier obstacles, then put a hard one every set distance to bring the average playtime closer to 20 seconds.
Also, I always appreciate a volume setting, so thanks for that!
Great entry overall