You have the correct resolution; now let's master the game. The 240x320 version has a unique physics engine. Unlike later Asphalt games that are arcade-slide-fests, Asphalt 7 on Java requires precision.
While the core gameplay remains the same, different "builds" of the JAR file offer varying performance levels: The "Official" 240x320 Build java game asphalt 7 240x320 jar better
Since official stores are gone, you’ll need to hunt: You have the correct resolution; now let's master the game