Isn't it possible to seperate the walkthrough from the main game (like a DLC or another maingame) with the price of 5 USD or free? Some games on itchio have it this way f.e. the games from Y Press Games.
I just tried it and itch.io won't let me, I can either make it more expensive than 25 USD or have it free for everyone who already bought the game (I would do that, but it won't be fair for the kickstarter pledges who already paid for it). So check the edit I made in this post for a workaround :)
