cool idea for new Godzilla game

Why not? Okay, I don't think you could make monsters like Justin Bieber, but I like the idea. 

It would be funny if you could make monsters, that a really small and weak anf monsters, that are bigger than King Gidorah. I think, combining monsters could be funny, too. 

I kinda like the idea. A game where you can customize your own Kaiju, upgrading it as you progress through the game. I imagine you'd start out small (like a MUTO) and as you progress you'll be able to mutate different areas of your monster for different effect. Objective wise you would be tasked with things like mass destruction, fighting other kaiju/creatures, locating nucleur sites to attain the aformentioned upgrades etc all while avoiding military opposition. The creature you take into battle will largely depend on the objective you're facing at the time and will allow players to experiment with "loadouts" to see which works best in the given situation. Later on in the game you could unlock Godzilla himself to fight along side you and then eventually as a playable character. I only say this cuz he's teh king of monsters and unlocking him is basically like an invincibility cheat, allowing players to just enjoy the carnage without the stress of potential defeat. It would work best as a pick up and play, arcade style game which relied on the spectacle of the destruction. Just provide big enough cities, a decent scoring and levelling up system and it'd be cool, like a modern day RAMPAGE!