Really amazing! The voice is convincing enough to the point to where I feel like I'm listening to the log of a madman.
However, the voice could need some work. It seems as if you're forcing the voice rather than letting it flow. It sounds like you're constipated, no offense. Don't force yourself to change your voice to fit the character or role. Envision the role you want to fill, and let your voice take control. You shouldn't have to force your voice into it, just ease your voice and your mind into the role.
In shorter terms, become one with your character. :)
P.S. I'm am not voice actor, but a music maker, so forgive me if my advice seems incorrect in some points. Although, I'm pretty sure it's the same concept for the both of us. Put yourself in a certain mindset for what you want to achieve. ^~^