Hi retrobrews, you could share it freely as long as it is in an unmodified binary form as available here on itch.io.
It would be great if you could also mention somewhere a link back to its page in itch.io
Cheers!
Gruniozerca is a Commodore 64 version of NES/Famicom mini game with the same title. Both games were created to support Polish 24h charity game stream - Gramytatywnie.
It was designed and created to run on a real hardware - Commodore 64 or Commodore 128 in C64 mode - and is compatible with both PAL and NTSC versions. Still you would be able to run it on any C64 emulator available for Windows, Mac and Linux that supports diskette images (like VICE).