I have a similar question to the other two asked. A year ago I purchased the preorder for $30. Is there any way I can pay $19.99 to have access to the Toru beta without paying all over again ($49.99)? When I clicked buy and input $19.99 it wouldn't let me and said I had to make a minimum purchase of $28.99 to buy the full game (that file is already unlocked for me) and $49.99 to have access to the Toru beta (that file was grayed out unless I entered $49.99).
Have asked itch.io about the ways to do it. Will let you know again once I've received an answer.
Okay, thank you!
Itch.io has responded, and "topping up" previous purchase isn't something that is currently supported. Currently, the only way to do it would be to ask for a refund, and then re-purchase with a higher value. If you want to do this, send me an e-mail to email@example.com with your itch.io account e-mail address (I'll relay to itch.io regarding the refund).