I'm not technically working on a game (I'm stuck in 2025 so naturally I was trying to port my last DOS game (and more importantly, the underlying game engine) to the web (a miserable experience, at least DOS makes sense and doesn't change their audio API every two weeks),
Aaaanyways I've got a tip:
Do you think Aseprite doesn't support 320x200 or 640x200 at 4:3 or 16:10 or god knows what weird aspect ratio you've ended up with?
It does! And it's one line! And I've been using it for months and it's almost perfect!
And someone made an extension that adds a user interface to that one line: https://heyitslollie.itch.io/aseprite-set-pixel-aspect-ratio