The game was very confusing on how to play, and it completely remove any of the fun one could've had playing. There is nothing that explains what the buttons on the left are and the only thing that makes sense from the table on the right side is the volume of the voice, the vowels made no sense. The art is definitely the strongest point so far.
Maybe some more arcade indicator would work, like having the words colored a certain way, combined with having the vowel pad having multiple colors or 4 rows of colors with in gradients.
I don't know if the icons on the left are supposed to be some sort of musical notation, but I didn't understand it at all.
You could check out Incredibox for some inspiration.
The game has a solid foundation, just needs work, well done!