Linux Mint Software Manager has not current versions

New to Linux Mint, but have a question. Just installed 0 A.D. and the gui for clamav, but they appear to be quite old versions, years old in the case of 0 A.D., even though software manager and update manager says everything's up to date.
Am I missing something, or doing something wrong? or does it just take a LONG time before updates get in there?
Someone recommended Linux Mint for its ease of use, so this has me confused.