Very nice! I love the city background in the last image. Very sweet colour palette and I like the shape of the buildings. Probably just me/or my browser but the idling head animation of the character sprite 'feels' very fast- which what you might be going for.  Their eyes are jiggling fast and I feel like I can't look at your character for a long time which gives me a feeling of disconnect and sense of anxiety or hyper/unrest from them. Which again might be what you are aiming for since they seem robotic/nonhuman. This comment isn't meant to be a critique!!!- just describing what I feel into words ^^  I am also about to design a character so I am trying to think about how to do it too. The lighting effects look super nice and I am a fan!