Thank you so much!
The game should scale up to 2× on a 1080p screen, but I've seen that not happen for one or two people and I'm not sure why.
I put out a new version a couple hours ago that hopefully fixed the crashes!
The art pack is gallery mode! :)
That's interesting about the movement; is the problem with actually walking around, or do you feel like you bump into things too much?
And the save file is stored in appdata or somewhere, so every version of the game (including HD vs not) will share the same save file.