I think it'd be nice to have an emote that had a really intense glare, in a "are you serious?" or "wtf did you just say?" sorta way. I've been trying to find an example, but nothing is exactly what I have in mind. The closest is something like Miss Kobayashi's "dead fish eyes," which is used as an emote in some discord servers I hang out in:
This is pretty close but not quite intense enough. What I have in mind is less bored and more shocked/annoyed/angry.
I'm also not sure how easily you could pull off this sort of thing in your style though, especially with the pixelated style. The eyes would probably have to be extra big to make small pupils visible. But I would love to see what you come up with!