Hello. Emacs included "pong" game, but "pong" is trademark. It is non-free. http://tsdr.uspto.gov/#caseNumber=76148525&caseType=SERIAL_NO&searchType=statusSearch I suggests that resolve trademark problem. (E,g Contact trademark owner) Thanks.
Blocking FE-Legal, This is trademark problem.
Pong game is removed from emacs. Like tetris. http://pkgs.fedoraproject.org/cgit/emacs.git/commit/?id=61c3d58e03b0a4123b8658eb9d056de4d042e07b