Hi Etoile!
If you wish to donate through the Itch page we'll send you a Steam key if you prefer to use it instead of Itch.io (it'll also be available officially here as well). But it will have to be for the 20 USD version, as the early bird was Kickstarter exclusive.
We will be keeping an ongoing list of donators/contributions leading up to the release, so you would be on a separate list to the Kickstarter backers.
Similarly, the Soundtrack (10 USD) and the digital artbook (5 USD) and the supporter DLC (5 USD) will be available if you donate the equivalent amount.
I'll add this to the page for other folks in case they have the same question.
Good day to you, Nysera Team! I was, happily enough, just paid by my employer so just want to let you know I'll be contributing today that 20 USD amount so that it be noted down in the contributors list <3
As for that Steam key, I'll gladly take that if possible! Thank you for all your efforts.
Edit: And done! A pleasure to be a small part of this adventure! 
264 days ago(+1)
Thank you so much Etoile! You'll definitely get the steam key on release :)
We greatly appreciate the support!
~ The Lazy Warlock