Here is the guide for how to play A Vibrant Melody as it currently stands if you have access during the early alpha. If you want access please let me know @Trev_Murray on twitter. The game is still very early in development, but some of the core ideas are in place, and it already is fairly fun to play. As with any alpha there are a lot of major changes coming to the game in the future.
Beware if you’d like to figure the game out on your own there are many spoilers ahead.
Move with the arrow keys, wsad or the buttons on a controller.
The unhappy creatures move on the beat of the music, you cannot move any more often than they do.
Moving into creatures sings to them, increasing their happiness.