Yes, that's currently one of my long-term plans with the character sprites. You can read more details about that in my recent devlog. It's extremely unlikely that I'll be adjusting screen resolution further down the road, for reasons detailed in that devlog as well. For as much work as it would take now to uprez everything, it would be far more the more art assets would need to be changed. Instead of taking months, it might take half a year, and I'm really not interested in spending that much of my life doing nothing but scaling already completed images (and I doubt anyone would want to pay me to do that either.)