This might be close to what you're looking for?
https://itch.io/docs/creators/refinery
Too often we've seen developers adopt an early access program as a way of collecting playtesting feedback and starting a source of revenue. There are a few problems with this approach:
- Your game is publicly available — You've launched something you know isn’t perfect, and not everyone who plays it will be understanding. You may be swamped with negative feedback and bad reviews that may damage the future success of the game.
- You've officially launched your game — The day you launch your game is one of the most important days in your game’s lifespan: it’s typically when you'll have the most people watching, talking, and buying. Very rarely do we see games leaving early access getting attention comparable to their initial launch.
For refinery we've completely re-worked how you can grant access to your project pages. The spectrum ranges from fully restricted to a list of people you specify use, to a password protected page, a secret URL, or completely open. Limited keys will let you give access to just your most interested fans, the people who will most likely be giving you the best feedback
(this might be another option you could look at but I think it requires the user to have an account)
https://itch.io/docs/creators/exclusive-content#how-you-can-use-rewards/giving-a...