No shooting. No explosions. But there are ideas here, furtively embedded in this first-person driver game designed by Houston-born artist Mel Chin and a passel of MIT programmers. You press the gas pedal and drive through the desert, where a "tree of life" dispenses golden balls to the tents of a nomadic tribe. In search of the balls, you drive to those tents, and through those tents, completing tasks, figuring out puzzles, overwhelmed by the detail of the tribes' rugs, mesmerized by the speed, hardly noticing how the new culture is colliding with the old. And when you've collected all the balls, well, nobody seems to know what happens then, because nobody seems to have collected all of them, even though -- and this is the best part -- the game, like admission to the museum, is free.