-The Soundtrack is pretty basic
-There's a lack of customizing the rides to be unique that shouldn't have been left out of the Gameplay experience.
-There isn't a WHOLE LOT of Replay Value to the game.
-Occasional problems with Touch Screen during some of the Mini-Games. Glitches.
Concept - Thrillville: Off the Rails is an Amusement Park Simulator DS Title. As a Simulator Genre game, you are given command over the development of your Theme Park. Designed for kids, you will check off Goals following humorous or silly story-lines. Even if you're an adult though, the story-line isn't so bad that the game is hard to enjoy. As it goes (with as few spoilers as possible;) Globo-Joy, Thrillville's Rival, continuously tries to thwart you in your park building endeavors. The concept behind the game is great, but it delivers best on the customizable Theme Park.
Graphics - I've seen better on the DS to be honest, but the detail of the game is still great. The objects are rounded and smoothed as best they can be, it's colorful and the Theme Parks are very well tailored to their theme. The attractions and their animations actually look appealing and fun to ride!
Gameplay - Building your own Amusement Theme Park from the bottom-up is a very enjoyable experience. The controls are simple and easy to use and master, as you'll use the Stylus for most of your play time. You choose what rides go where, with the only restraint being the size of the ride that's to fit in the chosen Build Lot. The Roller Coasters have some customizable options to them, such as how their exciting parts are look. You can even customize your characters and base to some degree! To go along with that, the game sets two different kinds of Goals down for you to strive towards: Mystery Goal (story-line) and Park Management Goals (side-missions.) Both sets offer decent challenges to overcome that flow great with the pace of the game. Rarely does it feel sloppy. There are also Mini-Games which each offer their own unique challenges and rewards. These Mini-Games are an excellent break from the job of building your Park. My biggest complaints about the Gameplay are perception problem from the Touch Screen, lack of fun stuff to do after the Goals, and that the game fell short of utilizing the DS's Touch Screen capabilities as much as it could. You go in thinking that you'll be able to use the Stylus to do many things in making the park and rides unique, but you can't even change the color of the attractions. And, as that is the "meat" of the game, it disappoints in those regards. However, the game still stands strong enough with those hick-ups that it's worth trying for the cheap price that it's being sold for now. It passes the time in amusing ways.
Replay Value - There's isn't much reason to keep playing or to restart the game, other than designing your park in novel ways. If you enjoy creating and customizing your park, then this is a good game that will keep you replaying until you've tried seemingly all customizing options.
Conclusion - Thrillville: Off the Rails is an entertaining game. It's not over-the-top fun, but doesn't let it's flaws shine through so strongly that it becomes bad. If you want a game that will keep you playing for a long time, this probably isn't it, I beat it in less than a week. However, if you want an entertaining game that gives you most of the control over the experience and is good passing the time away, then this is a great buy. So go ahead and give it a try.