Half a driving game, half a garage. You start with whatever is rusting in the junkyard and earn coins on each run to spend across ten categories of parts — engine, wheels, suspension, turbo — until the thing that could barely climb a slope is clearing ten driving worlds. The career layer adds short contracts and experience for driving, collecting and landing jumps. Junkyard Builder is paced so the next upgrade is always one run away, which is either the appeal or the complaint, depending on the day.