[Couldn't type a comment on the other video to respond back]
For me, I'd say that the voice is fine. But experimenting with it wouldn't be bad either.
Trying new things could improve the desired result on your end.

[On to this video]
I found the facial expressions interesting since there is no mouth, just a speaker. Being able to convey emotion without a proper mouth is cool. I also think that the upper body movements were good.

Also, Team Fortress 2 is what I choose.