O.K., I'm making this up as I go along, so just bear with me.
Alot of the above suggestions are great, but I don't really want TOO much RPG stuff. By that I mean overhead views and turn-based battles. Essencially I want something like SM64, but HUGER!
You'd be able to pick your character at the start, each with different strengths, weaknesses, and abilities. I'm thinking Mario, Luigi, Toad, and maybe Peach, though we might just want her be captured again (but we would put a new spin on it!). It'd be so cool if there'd be a multiplayer mode where up to four players go through the adventure at the same time, as the different characters. It'd be hard with the split screen, though.
My general concept for this game sounds kind of strange at first. I'm just thinking of that old Miyamoto-style whimsy. I was thinking there'd be this sort of "sky world" that Mario (and the rest of the characters, though for now on I'll just say Mario) flys around in Wing Cap style. It'd be a cross between Rainbow Walk from SM64 and Rainbow Road from Mario Kart 64 (there'd be "space" areas as well). This would be the main overworld. Mario would fly here and warp to the different worlds of the game. When I say worlds, I mean WORLDS! Not just levels, but worlds with tons of worlds! These worlds would each have a distinct "flavour" or theme. I don't mean theme as in "Desert World" or "Water World." The worlds would each be more diverse and detailed, like our own real Earth. They just have to be different somehow. A world could be mostly covered in water with tropical island, making a mix of ocean levels and jungle levels. The world Mario starts off on, the Mushroom World, would have plains, mountains, deserts, oceans, etc., but with a whole lot of big mushrooms, which is why it's called "Mushroom World." Yet another world could have lots of mysterious ruins, statues, and temples whoose mystery you must find out, but still have diverse terrain. You should get the world concept by now.
Anyway, each world would have lots of areas (it's a WORLD), each with its own secrets and objectives. There'd of course be towns to visit and people to meet. The different worlds would have a main objective, which would end with a battle with the world boss. But the quests should be COMPLETELY different from each other. The world quests can't follow a pattern like "enter location, find out problem, go through begining quest, learn song, play song to enter dungeon, beat boss and everybody happy" (this is what Majora's Mask was like).
Of course, there should be a reason for Mario & co. flying through this sky realm to these different worlds. Might have something to do with stars. You can figure this out.
I also want a return of the classic gameplay of the old Mario games, but brought to 3D. I want super mushrooms that REALLY make Mario grow in size. This would make him do more damage to enemies, smash blocks, and jump higher to reach secret areas. I mentioned blocks back there. I want the return of block platforms floating in the sky, just like in the old 2D games. Mario should jump higher in this game than he did in SM64. Another thing about blocks is that there'd be different types that can only be broken certain ways. Brown blocks can be broken by regular Mario. Yellow blocks can only be broken by Super Mario. Red blocks are broken by Fiery Mario's flames. Green blocks need koopa shells thrown at them. And maybe Golden blocks that need to be rammed through by Mario when he has a Starman. This arrangement of blocks would add more strategy to levels.
Those are my thoughts. There's a lot here, but I hope it's worth it.
P.S. I just registered yesterday. Hi everybody!
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Never have I been so wronged. It is time.
I will show you my real form.
I will show you my true power.
I will teach you respect.
AND I WILL HAVE MY REVENGE!!!
