So with Thrillville, the vision was to produce a hands-on theme-park "experience" in a box, and to thereby create something new. Thrillville is hard to categorize. It has "sim" elements, party game elements and many more, all mixed in with some action for good measure.
In Thrillville, the whole park is interactive - you can talk to/flirt with all the guests, decide what attractions go where, what colors they are, how much to charge, and from the humble restroom to the first-person shooters, to the race tracks, to the golf courses, to the craziest coasters you can build, you can walk around and interact with it all. The key to this was to make all the different "mini-games" that you play high-quality gaming experiences in their own right, and to integrate them with the main game so that they flow naturally together. How you do in them has some bearing on your overall game - even going up to a guest and challenging them to a match.