This thing traumatized me from the entire NewGrounds website as a child. Hell, I'm over half ny 20s today and I still get the heebie-jeebies!
There is something about that animation that just... no, it's not ultra-realistic like RE8, but perhaps that is part of why it feels so wrong... uncanny valley perhaps?
Anyhow, it is still a gem(?) for the time it was created.