It's very good. But try some more keyframing and less tweening to make a smoother animation. If you don't like drawing frame per frame you can chose to hide some movements. For instance if you want a stepping guy but don't want to animate it. You can hide the legs and only animate the upper side of the character. Anyways I guess it was a good exercise to animate all that. I really appreciate your determination

Did you screenshoted the minecraft rooms and change they're tiles? Cuz that's what it looks like, but anyway. Nice animation, your style looks fun.

I like your drawing style, but I feel it was just a way of emphasising the sound. This way, it becomes more of an auditory experience, mixing sounds with music, that calm music box with some harsh strings. The animation doesn't have to be smooth if it doesn't match the atmosphere.
My favourite part was the ending, when the boy remained silent (still that sound-oriented perspective). You did a great job!

This was a pretty good animation, the only thing is the tweening was really heavy.

Yay naked slenderman.