Pokemon. There are a few things I've always wanted to be included in the games. Plus, I don't trust my ability to write a story any more complex than that.
An RPG, no doubt.
Low level enemies would be zombies or something.
Party members would have anime style portraits
I would not release it until I was positive that it plays well.
A RPG based off of an original novel turned RP. Free roam with a vast quest line and superb character creation control, as well as decent conversations with a voice for your character (silent characters annoy me...one thing about skyrim I don't like.)