I like it. Hardcore challenge, responsive controls, tight jump, easy to play. Tough to master.
,A few suggestion, though. While I like the challenge, I think you hurl the player in way too fast, especially for a first-time player. Give them a chance to understand the game. Throw two rings at them to begin with. When those are gone, three or four. Then five or six. Once the score closes in on 10, you can start working up to where you are throughout the remainder of the game.
I don't think it ruins the game or anything having it all happen at once, but I do think it would make it easier for players to get hooked, and it would help to suck people in by having an increasing intensity rapidly pulling them in. Seeing the playing field start small and then quickly fill up with more, more, and more rings builds to a frantic level, and is much more effective than trying to hit the player all at once. I think there's a reason most games have worked that way for decades.
Also, it says "avoid them until you have jumped over them." That makes it sound like green rings should be safe, but making contact with them often ends my game. What did you intend? I do think they should be safe. Caused some pretty stupid failures.
But slow build-up or from the start, I do think this is a great challenge, and hardcore gamers will enjoy trying to beat their score.