JGO is not meant to be a host for any (small or big) games. It’s a place to demo/share your WIP. 10MB might not sound like a lot, but remember JGO runs on a VPS where harddisk space is limited, just like datatraffic. If it would turn out to be necessary, we’ll eventually move to a situation where old data is purged automatically.
Regarding your highscore-PHP-script (which would mean running untrusted code on the server…), no, nothing like that will ever happen 
The problem with ‘approval by moderators’ is that it is an excellent attack vector to infect our moderators. :clue: