The tag is present in Lintian version 2.104.234. That is the most recent version we know about.
The file is owned by the games group but is not mode 2755. If a game does not have to be setgid games, it should be owned by the root group like any other executable. This executable is either owned by the wrong group or is not setgid when it should be.
Refer to Debian Policy Manual section 11.11 for details.