I know it doesn't work because the game was made for an older version of windows, but I don't want to install a virtual machine just to play that game. Is there anything else I can do?
As far as I'm aware besides not being fullscreen, no, especially since that game came out in like 07 and everything's pretty small back then, supposedly yanfly core engine has wide-screen support but I'm not sure how you'd go about with it, you might have to decrypt and/or unpack the game files first, also because I've never tried it myself and the fact you're on Windows 11.