Are people using a mouse and keyboard going to play against people using a controller? The results will be hilarious (in that anyone using a controller wont stand a chance). Everyone will be forced to use a mouse.
There have been games that have released with this allowance. They achieve balance by offering powerful aim-assist to the gamepad players.
In any other context that would be the foulest cheating... but in the context of game-design for vastly different interfaces, it's a perfectly reasonable handicap.
You wouldn't be able to (and can't) do this on competitive PC/Steambox games though because you can just fake it on PC, so gamepad players would never be able to compete.
Wait, that doesn't make sense. Super Mario Bros. uses digital inputs, not an analog stick, so it's essentially the same as a keyboard...Are you saying keys are somehow different than controller buttons?
Well, yes. There is a different feel to using a d-pad and using four distinct keys, and it throws me off when I'm playing a 2D platformer. In SMB, the inertia feels totally wrong using the arrow keys or WASD.
I agree, but I think it's because a d-pad does two things: 1) it lets you press two directions at once with a single finger (all four diagonals are actually two presses, e.g. up+left); 2) it stops you from pressing two opposing directions at the same time like you can on a keyboard, e.g. up+down.
Once you get used to these limitations or find a game where diagonal movement isn't required (not sure about SMB), it's really quite tolerable to play a 2D platformer with WASD or arrow keys. But you're still right it doesn't quite have that magical kinesthetic quality that a d-pad does, and I'll always choose a gamepad myself.