This feels like a question for a copyright lawyer. One could argue that you're still making money from the project, so it's not non-commercial use. But, the wording in the US BY NC implies that if the main point of the project is not to earn money, donations are fine.
As someone who creates assets, if I were you I would reach out to the artists who created the assets you want to use. They should be able to give you a better idea of what you can use their assets for