Midi files like this always bring me back to those early 90s point-and-click games. They certainly had a mysterious charm about them. Unless that's your thing, maybe you should look into higher level audio workstations like Ableton, FL Studio, Sonar X1, etc. They're totally worth the money. And if you're really strapped for cash, there are some really good free vsts floating around on the web that can add to your sound.
But like I said, if that's your thing, then it sounds very nice for what it is. However, midi can't really take you very far in terms of creativity. Cheers!