Another important concept similar to what Warp is talking about is
Scènes-à-faire, or the idea that if something is necessary in order to make a work with that goal, then it can't be copyrighted. If in order to make a run of Ghost and Goblins as fast as possible, you are required to use certain techniques, then they can't be protected.
But you also bring plagiarism, which is an academic standard and not a legal one, so let's look at that.
Really, in academic writing, the purpose of citation is to prove that you aren't pulling ideas out of your ass. In other words, to show that you did proper diligence and rigorousness with research. It's a method to help others check your claims, and it kind of saddens me that it's usually framed as a moral issue, but whatever.
If I were to use your work in an academic paper, I would quote you or state your ideas, then I would mark where it came from in the moment, and credit you fully in works cited (in some standards, the full credit is in the moment as well). I do not list you as coauthor on the paper. The only writer of the paper is me, I just used your work to help make mine. For multimedia projects, often the standard is to just include the works cited with the in the moment citation standards being less stringent.
So by academic standards, all Dreamyao needed to do was credit you for your previous run. He didn't need to make you coauthor for that.