There have been a lot of MMOs released in the past 4 or 5 years that have seemed to have flopped, and rather quickly for that matter. It's always frustrating to us, as gamers, to feel like we've wasted 40, 60, or even over 100 dollars on a game that all of our friends end up leaving after about a month. Why do they leave? Well, there are usually many different reasons, such as lack of end-game, not polished enough, pushed out the door before it is ready and more. But there is always a missing component as well... cats.
If there were more cats in these MMOs, I think it'd be less likely to fail. Think about it. They are all over the internet, especially on photo-sharing sites like Reddit, IMGUR, etc. I'm being honest when I say that I have more cat photos saved on my computer than I do of my friends and family. Hell, I treat my own cat like a princess and she is known by my stream and YouTube viewers, as "Darth Giggles", a named also dubbed by them.
Cats are the perfect antagonist to anything. It's just in their nature to be that way, especially since they are prideful, yet regal, agile, yet often clumsy. They are entertaining to watch and be around despite the fact that they sleep for half the day. They are, overall, loyal companions even if they are demanding. We as humans have to accept the fact that they will one day take over the world.
But back to games. A company could even stage a cat versus dog war. This goes beyond just having a cat or looking like a cat, but fighting a REAL war against other factions (dogs and mice - because 2 factions are so last year). This is about the focus on the mentality of a world where, if cats where to take over, this is what it would be like. Downright dirty. Despite that there'd be grey, poptart cats with rainbows coming out of their behinds. It'd probably be a pretty grim and hardcore world. I dare even say more hardcore than your CoD or MW settings. I DARE even say more hardcore than WoW.
It'd be like taking the old Batman series, with the most loved and hated villain, Joker, and turning it into the dark, grim, yet real universe. Transforming Joker from a prank-loving, dangerous buffoon into a philosophical sociopath would be astonishing. Putting cats into these fantasy-filled environments would transform these (mediocre) games (at best) into spectacular works of art.
Changing gears for a minute, you do see games reach moderate success because of their use of the cat. Take WoW for example. One can play a Druid, a class that transforms into a feral cat. The feral (DPS) spec is the best spec in the game. Ever. Somehow it is always overpowered... the Druid, that is.
Then you have League of Legends: Nidalee also transforms into a cat. Nidalee is also ridiculous to play against. Have you ever taken one of her spears to the face? Yes? Then you know exactly what I am talking about.
Last, but not least, you have Guild Wars 2 where you can play a Charr. Now, arguably GW2 actually took the use of cats and their story the furthest it has ever gone because, not only can you PLAY a cat, but there is an entire story and city based ON these cats. How amazing is that? And look how successful that game is doing. Granted, it just released like two weeks ago (but that's neither here nor there).
Now just imagine if someone made an ENTIRE GAME like this. Instantly the REAL, next WoW killer.