When I got Thrillville, maybe I had the wrong idea in mind, but it definitely wasn't what I was wanting from a game. With Rollercoaster games, I had the idea of Rollercoaster Tycoon in mind where design was endless making the coasters.
But instead you're a character inside the game with a very limited character design. Talking to the characters inside the game is pretty fun in itself but eventually wears thin on you.
The mini-games are pretty fun (the cheerleading and the mechanics were very fun) but otherwise the game fell very flat for me.
I'd say rent the game and try it before you buy it; you might like it, or you might have different expectations like I did.