You can already filter by genre, but currently genres are disabled due to abuse, as for release day, that's what the release ID is for. For systems other than NDS and GBA it doesn't really matter, nor do we have the information required to do so.
Suggestion? Instead of making it so user's can put these in-how about we import from gamefaqs at some point-and have user's make topics here every now and then to prehaps contest it? Otherwise it'll only happen again-the non-forum user's will mess it up. I can help importing if required-a bit at a time but I might as well put my activity here to some use.
Because finding the gamefaqs URL for the game is a lot of work, easier to just let users add/remove it.
