Interesting idea for putting a play area on asphalt, concrete or hard soil in a temporary build. The tires and rocks can be removed, and the sand and rocks swept up. Interesting idea for day cares in urban settings without access to grass or soil.
Repair a cracked driveway by filling cracks with asphalt patch, then coat the surface with a blacktop refinishing compound, available at hardware stores. For a more involved project, consider upgrading your driveway with a decorative border of concrete or paving stones.