You're making shit up. Copyright is very simple. Copyright doesn't protect ideas. (Patents don't protect ideas either btw, no law does.) It doesn't even protect likeness! Copyright only protects the exact image, the exact sound, and the exact text. That's it. You are allowed to cite text without breaking copyright. You're allowed to mix sound and art also without breaking copyright. You're basically not allowed to cut-n-paste things verbatim. That's it.
So if you draw something that is reminiscent of pac-man but isn't a direct cut-n-paste of the original graphic, it's not a copyright violation. It's that simple.
There is no such thing as "IP." IP is a bogus concept that doesn't exist in law. It's more like a dream of some greedy people rather than reality. The dream is that virtual things and ideas could be privatized. It won't happen.