An RPG game, in Oblivion's style of leveling up and whatnot. It should have some great, graphically intense environments. The environments would vary quite a bit from one another, for example steampunk cities and vast, nearly empty deserts. It would be humorous, and yet still have a serious, powerful, and overall original plot. Other than that, the map would be overly extensive, it should be highly dynamic and constantly changing, and when you do things, the world should respond to it in some way or another. The game would be dramatic, and feature things such as betrayal and love, and as the mood of the main character changes due to these things, so the gameplay would be affected. For example: If your character is enraged, you may move faster and your attacks may become more powerful.
I would almost say to make it an MMORPG, but I hate it when everyone is the main hero.
No mother fucking guns. Guns take half the skill out of killing people, because it gives you a chance to use distance to your advantage, and also get one-shot kills too easily. Bows would be okay.
There would be a realistic amount of gore in it, as one person can only bleed so much. Overall, it would try to be pretty realistic, and yet continue to include all the non-realistic things that can help a game out. For example, part of the main storyline may be about killing giant monsters, possibly similar to the Colossi in Shadow of the Colossus.
It wouldn't be a hard game to make, it's just that developers need to be more inspired than they are.