As long as it does not contain any outside URLs - meaning a website that is other than MPGH, then it is not allowed.
If it contains a link to another rival hack site, then it is not allowed.
Logo's may also depend, too. If the logo somehow relates to a rival hack site, then it isn't allowed. It some cases it might not be.
If the hack is packed, you must provide us with an unpacked version.
The hack should not be connecting to the internet in any sort of way.
That should be about it. Make sure the hack does not have any of these. If you think it doesn't have any of these, then you're good to release it.