Great music and sounds!
Controls aren't that good. I see your point, you wanted it to be hard to dodge obstacles sometimes. But I think that high speed isn't the way to go in this situation, because it just bothers you when you just can't catch our breath in/out. I'd recomend to make this ball moving all the time, but lower the speed and let player control direction. In this way you really need to focus on your ball (and this is the whole idea around your game, right) to dodge obstacles, but you're still able to manuvere more freely. Also screen wraping would help a lot.
I didn't like that game gets harder after sometime. First of all, it's just too uncomfortable when you're moving on supersonic speed and can't see anything, Second of all, I just can't see a reason to make game harder with time. Just make it hard enough to be interesting from the start to the end. I loved the pace it had at the start or around one minute mark.
Also, meditation timer would significantly improve the experience.
Good game anyway! All that I said is minor things that you can improve. Visuals are nice.
One more thing I could recomend to you is to "control the chaos". I mean, make random a little less chaotic. It doesn't feel good when sometimes your breath in/out are on the different ends of the screen and one of them is blocked by one of the stressful words. Feels just unfair, so you can work on this stuff.