I donot think that this application is illegal as long as the author did not use any original art work and trademark (if it still applys, trademark needs to pay

I donot think that this application is illegal as long as the author did not use any original art work and trademark (if it still applys, trademark needs to pay to extend it, right?). 1. Any patents related to pacman expired already. 2. Copyright law does not forbid recreation of original games. The JS author just need to make sure all the code/art was created by himself. Please point out what is wrong about my understanding of the law system if there is any.