It's really hard and I suck at it. But I did try a lot, which I think is a good sign, that I wanted to keep trying despite how hard it was for me.
The speed changing ability is neat, though it seemed kind of weird to me at first. It seemed like it was just better to be faster. But as I played I realized this was actually pretty useful. Would be nice to have a sound go with speed changing. Actually, it would probably be good to have three sounds, one for each speed level. I think the clouds and mountains in the background of the first stage are too noisy. I'm bad so I'm not sure if this might have affected my ability to see and dodge projectiles but I do think it's a little distracting.