Looks good so far, enjoyed it.
The hit detection feels good, but the charts are fairly difficult while the grading is very lenient. I can almost clear a song using only 1 button and ignoring the other 3 directions. I would make the charts a little easier and the grading stricter.
The words that pop up when you hit a note can be hard to read. You shouldn't allow more than 1 word to appear per arrow so that they don't overlap. Giving them an outline and making each one a different color would also help.
And I think you could do more with the character's expressions. Maybe their expressions could change if the meter falls bellow 25% or if the meter is kept above 90% for a while. They do get a little blush as the song goes on but I'd like to see more changes as the song progresses. Maybe increasing the speed of their breathing/idle animation.
BUGS:
Some double notes will start playing the animation for one direction but then get cut off by the animation for the other direction. I think it should only play the animations for one of the directions. I also think there needs to be a unique animation for the [left/right] and [up/down] double notes where the sack is stretched out.
Sometimes the animations would get really choppy. The animation for the sack lurching would not end on the last frame and instead show the first frame again at the end of the animation (not sure what causes it and I hope I'm explaining it correctly).
The chest and face animations for the raccoon cutie will get interrupted whenever a note is pressed.