itch.io

Below my attempt of rephrasing the current Rules.txt:

Copyright © 2020 Noraneko Games (@NoranekoGames, noranekogames.itch.io)
All rights reserved.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this artwork to use, modify, and/or distribute this artwork subject to the
following conditions:
- The above copyright notice, as well as this permission notice shall be
  included in all works, that redistribute this artwork partial or in total,
  with or without modification.
- Credit must be provided to Noraneko Games in the media using this artwork
  itself or a note accompanying the distribution either as part of the
  distribution or prominently displayed along with the distribution.
- This artwork shall not be used for illegal purposes or other purposes, that
  may reflect poorly on Noraneko Games.
- This artwork shall not be used commercially without Noraneko Games' prior
  written consent.
  - For the purposes of the above, "commercial use" shall be defined as any
    usage, in which the user generates revenue for themselves or a third party
    either directly through the charge of money or indirectly through
    advertisements, cryptocurrency miners or any other tool, that effectively
    generates revenue.
    Not covered under these terms are fees charged by an ISP when downloading
    a copy of this artwork or the cost of physical devices that the artwork may
    be stored in.
  - As an exception to the above, this artwork may be commercially used in
    games after Noraneko Games has been informed about the usage.
- This artwork shall not be replicated in print without Noraneko Games's prior
  written consent.

Notes:

1. The point regarding credit would be simplified a little if you disallowed notes "on a website" and required credit as part of the distribution. I suppose you allow it, so that others can retweet your work while tagging you, am I correct?
2. I'd drop the part about informing you from the commercial reuse in games. Since one would have to wait for your acknowledgement on the information before one can actually start using the assets commercially, it is in fact not too different from requiring written consent.

In case I am missing something, please do not hesitate to inform me.