A neat concept. It did induce a minor trance, though the introduction of the blue and yellow notes is rather jarring and requires me to focus out of trance to attempt to hit them properly, which isn't conducive toward the game's purpose.
My advice is, in the full release- or maybe even a future demo- is to gradually introduce the notes. A good antepiece to this might be to have a string of notes (Up, Right, Down, Left), followed by a reminder of yellow and blue note keys, and then the same pattern with blue and yellow keys. (This pattern, coincidentally, follows a spiral pattern.)
Overall, it's promising, and I hope to see what it looks like upon completion.