Thanks for playing! If you're interested in implementing a leaderboard, try Lootlocker. That's what we used for our game , and they have a YouTube tutorial that shows you how to get it all set up :)
As for animals/humans, the humans are your lives. So having a chicken get eaten doesn't hurt you as much as having a person get eaten. We definitely needed to find a way to make that more clear, though. And to indicate to the player that they can pick up the monsters and sling them into portals to get rid of them.