In /etc/passwd there's a bunch of users which are there on every Linux install. The purpose of some of them is obvious, but some of them it isn't. E.g

Anyone know what the intended purpose of those users are? I'm sure I once read something somewhere which explained the purpose of such users, but I've completely failed to find anything close via Google. I think some of them pre-date Linux. The daemon user is also present on Solaris.

I'm guessing daemon is intended as a convenient account for you to run daemons under that you don't want to run under root.

They seem fairly obvious. As you say, "daemon" is an account to run daemon's under, and "games" could be used as a limited account for just playing the various text games that have traditionally been installed on *nix systems.

Like you guessed, this sort of thing dates back to the Unix days, and exist today purely as convention and for backwards compatibility for any scripts or programs that expect them to be there. Nobody plays the old text games anymore (let alone sets up an account dedicated for it), and daemons are usually run under their own accounts or "nobody".