The only thing I know is if I were a game designer, my games would suck. But I'd probably go with an RPG or a vertical bullet-hell (or not) shooter.

Everything will be like Tiny Tina. Everything.

rpg gamez with ponies i would name it
SUPER LEZBO PONY ADVENTURE 3485! (SLPA3485!)

I'd do Creepypasta dogs :3