I tried swapping left and right Alt because it makes more sense to me that if I nudge the table from the left (using left Alt), it jerks the ball to the right, not the opposite.
But when I tried to set it up like that, for some reason, as soon as I hit my right Alt key, Big Race binds both Right Alt AND Left Ctrl to left nudge. Which, as you can guess, makes the game unplayable.