NBA Jam keeps the court clear by forgoing most of the team and using a 2-on-2 system. Since the game is still fundamentally basketball, there's little point in going over the basics -- but there are plenty of interesting twists on the formula that make Jam particularly novel.
Controlling a character is as simple as moving the D-pad and using three buttons. Midway could teach modern developers a lesson in simplicity -- one button controls shooting on offense and blocking on defense; the other controls passing on offense and stealing on defense. The last button activates turbo, which can be used in conjunction with the other buttons to do super jumps, knock down members of the other team, or score with backboard-shattering Jams.
A modern-day reimagining of NBA Jam isn't the easiest thing to conceptualize, but if any console could balance the fun simplicity of the gameplay and a style of play for a new generation, it's the Wii. Jam was especially awesome as a multiplayer game thanks to its multi-tap suport, and legendary commentary including "From downtown!" and "Boom shakalaka!" is still a part of pop culture.
A remake of NBA Jam could easily succeed along two totally different paths. A WiiWare version, featuring upgraded graphics and online play could retain the 2D style of the original. It could even be played with the Wiimote NES-style, using 1 and 2 for actions and the trigger for turbo.