Sorry I'm not playing the demo!
https://itch.io/docs/itch/integrating/updates.html
For now, when uploading a new file on itch.io:
- Uploading a file with the exact same name will:
- Replace the previous one
- Keep the stats (download count)
- Temporarily make that download unavailable, while it's being uploaded (known issue)
- Uploading a new file and deleting the old one will lose the stats, but there'll be no downtime.
- Don't forget to tag it with the right platform again
- Alternatively, 'hiding' the old download will allow you to keep the stats for a while.
Needless to say, this process isn't ideal for often-updated games, and we recommand using butler instead.