Niiice!!!
2nd, I liked this one very Much:) Try to bring out more of these movies. As to Tropzilla, I think that the song that you are referring to is the one from "Pirates of the Carribean, The Dead Man's Chest", which played when the Kraken took down the Black Pearl with Jack Sparrow still aboard. My advice is to rent and watch the movie to confirm this. it sounds very close.