Im gonna the part where i beg (cause i know that doesnt work) and get to my reasons why i think humans should be in YL2. 4 simple words, Monster girls/guys. The possibilities in this category are grand due to the mythos behind ancient creatures like the Minotaur, gorgons, harpies, demons, werewolves, and kappas. Not to mention the Imagination of thousands of people who come up with crazy monsters, beasts, creatures, and anthros. There's even a internet page all about monster girls here, so if you used that you could get references and ideas as to what you could throw into YL2 (if you want to).http://monstergirlencyclopedia.wikia.com/wiki/Monster_Girl_Encyclopedia
. With this, the furry fanbase, and your groups creativity and skills, the possibilities could be near endless!
There's also the obvious idea of branching out your fan base, leaving it as just a furry based game,(which i have no problem with, i love this game) it can just be a bit... limiting. If you branched out a bit into that category though , im sure there would be tons of people who would flock to YL2.