You can't copyright gameplay. The sprites, the characters, the dialog, the logos, the music, and things like texture maps and so on can be protected. But the design of the levels can't be. Nor should they be.
Games borrow from eachother. It would be like if... Chess copyrighted the chess board and sued Checkers.
Games borrow from eachother. It would be like if... Chess copyrighted the chess board and sued Checkers.