Wii Fit Plus has a unique mini game called the obstacle course, or something similar to that extent. In the game, you control your mii character getting through obstacles by stimulating running movement by walking/running on the wii balance board. Jumping is created by bending your knees and then extending. The game works by your wii character going through a straight line running past several obstacles, like the name implies. Obstacles include swinging pendulum balls going left and right, rolling log-like structures going towards your mii character or simply left to right, and gaps you need to jump over including moving platforms with gaps between. Your goal is to run and get to the over side by moving your character forward basically through a straight linear path.

Wait a minute, isn't this what a 2D Mario game plays like? You control a character that runs through a straight linear path past multiple obstacles, platforms, and moving objects to get to the other side being the goal? So why not make a balance board game that plays something like Mario or even a Mario game controlled by a balance board? Here are some of my ideas for the gameplay.

Running and walking: Movements based on how quick you lift and lower your heels or simply set your foot on the balance board. Running forward requires you to lean forward at first, and deciding to run backward requires you to lean backward  and then continuing to run or walk normally. The balance board is able to be faced horizontally long, making this gameplay feel normal and comfortable (even though mario is running left and right when you are running/walking forward) There will also be a returning P bar like Super Mario Bros. 3 to measure your running speed. In this way, you don't have to lift your feet in multiple speeds, but rather three, meaning walking in steady pace continuously equals walking. Shifting your heels a bit quicker than a steady walking pace continuously will make Mario run faster over time. This creates a untiring way to run.

Jumping: Bending your knees (slightly) and extending your knees to a standing position while standing still, walking, or running. This was easily able to accomplish in the obstacle mini-game and there shouldn't be a problem here.

Flying: Flying will require you to hold your arms out while moving them very little and slowly to stimulate hovering just like the chicken mini-game in Wii Fit Plus. To fly forward, lean forward, and to fly back wards, lean backwards. To fly straight up, position your body straight up. To stop, lower your hands down slowly or quickly to judge how fast Mario will fall back down.

Fire balls/axes/punch: Simply punch out your right hand while holding the Wii-mote in your right hand or left hand and watch Mario stimulate the same action. You must lean forward with the same side leg only to throws fireballs and punches, making them some time to perform these actions w/o spamming, although fireballs and axes are limited to 2 on screen at max like every other Mario games.

ground pound: as you jump in the air, and as you are in the air, simply, bump your hips backwards (slightly) to motion a ground-pound

wall jump: right after you jump on the wall after extending your knees (making you revert back to a standing position again), lean on your tippy-toes instead of bending and extending your knees again to create a quick wall jump

Kick: As you kick, shift your body with the leg you aren't kicking like in the kung-fu wii fit plus game. (example being kicking with your right foot requires you to shift weight to the left at the same time) You can also kick during jumping and the same goes to punching.

sliding down a hill/crouching: bend your knees down on a hill to slide down and crouch when on a flat platform by bending your knees like you would for a jump. You do not need to actually bend all the way down. You can run while crouching and jump by leaning on both tippy-toes of both feet. Obviously the former will be hard to do, but what Mario game lets you run while crouching before in 2D?

Measure of jump height : As you jump, move your arm (the one with the hand holding the wii remote) in the air like Mario does while making the leg of the same side of that arm leaning forward. The longer your hold up this position, the higher mario jumps, and as soon as your put both down, the height will have peaked and Mario will fall down like previous games. The gesture will seem like you are punching in the air with your right/left arm while leaning on leg with that corresponding leg.

cartwheel jump: While running forward, lean back quickly while moving your arms back as well to stimulate a cartwheel jump. The arms should rise back ward like an arch as your body naturally arch backward from this pose. Will register if you do it quickly and there is a set jump height for this like every 3D Mario game.

Backflip: bend your knees down (not all the way) for a crouch pose and shift your heels back ward quickly for backflip jump. Because of this you have to lean backward and then bend your knees for a crouch and walk to make mario walk backwards while crouching

So, what do you guys think? Is it possible, or will it be too tiring, or will the motion not register and feel too awkward? Discuss.

Its possible but it would also be very tyiring, maybe they could include a smaller version in Mario Party 9

This would be impossible to realistically controlz.

Natal would be betterz.

the balance board is barely responsive enough for the wii sports resort activities, i doubt it would do any good.

Your control issues stem from the fact that your using the balance board with Wii Sports: Resort, Im sure if you used it in a game it was made for you would get better results ; )

It would be possible, but it's mostly limited to leaning to certain area which the balance board does a really good job at.

I know it's tiring, but did you look at the movements/poses I listed for each control aspect? They all revolve around leaning into certain areas, something that really doesn't really take too much effort if conducted not too excessively.

The only thing that would actually require effort would be cartwheel jump, though, IMO.

Edit

It's 10 o' clock here so I'm going to sign out, now.

But why go sidescroller? Wouldn't it be more natural if you saw the action from behind mario?

Seems like gaming is going in this physical direction. What does this mean for those of us that have sat in chairs with gamepads in our hands for the last thirty years playing rpgs 10 to 12 hours in a row while eating chips and cheese covered popcorn while gaming and that would probably break balance boards if we stood on them?

Last time I went to a doctor my bp was 129 over 86 and my resting pulse rate was 101, so I don't know how I'm going to play games in the future if this embracement of motion controls keeps going in the same direction.

Nah, there'll always be gamepads and lay-on-your-couch-stuffing-your-face games :P