Hey great work! I'm not a big fan of metroidvania games myself but from gameplay I can see this is great.
I am a somewhat proficent linux user, and I have a suggestion. Rather than using a VM try using a usb stick with Ubuntu flashed onto it. It has a feature where you can run a trial version off a usb stick/CD/DVD etc. Just be warned that you will need a second (FAT32) usb stick/drive to download files onto as Windows disks use NTFS which cannot be read by linux without other drivers/apt packages.
Sorry for information overload ;) Hope you can properly test this!
PS: If you can compile it into a .deb package or the like that would be good