The Wizard of Oz is a beautiful, lighthearted, and fresh RPG for the DS.
The gameplay in Oz is quite straightforward overall. You use a trackball system on the touchscreen to control Dorothy as she makes her way down various paths. You can control her speed and direction, just in case you want to avoid a particular enemy at a particular time, and being able to affect her speed is important for making necessary backtracking quick and painless. As Dorothy and the gang travel down these paths, they'll encounter many enemies, which you will need to battle to proceed and to level up your team. You use the touch screen to interact with objects, select battle commands, and even teach Toto a few new tricks. The entire game is touchscreen controlled, which makes for a smooth and seamless experience. It feels very natural, once you get used to it.
The battle system is simple but works well. Certain characters have certain affinities, so they do better battling certain types of enemies. For instance, Dorothy is best against ghosts, Strawman is best against aquatic enemies, the Lion is best against shell-based enemies, and the Tin Man is best against plant-based enemies. The game also uses a ratio system, so that the more powerful a character, the fewer times they can be used in battle per turn. It makes a lot of sense and makes battles more interesting--which is good, since you'll have many, many short battles and some lengthier boss battles throughout this game.
The most complex part of the game is navigational, as there are many paths to take (and you'll want to keep track of which paths you've taken and what's there). The game provides signposts, which you can mark with your own system of symbols using icons that are provided (whatever makes sense to you), so that you can keep track of such things, but I wound up making a few maps/notes on my own as well. You'll often encounter gates or obstructions that can only be cleared through the use of various switches, and most of these switches can be triggered only with the appropriate elemental (little spirits of fire, earth, water, and wind that you'll pick up along the way). You'll sometimes have to do some backtracking to open gates after you've gotten the appropriate elemental. But again, because you can move quickly, as long as you keep track of where you're going, backtracking is relatively painless--and often quite fun, actually.
Finally, as I mentioned in the first paragraph, this game is beautiful. The environments are vibrant and lush, and all of the characters and enemies are colorful as well. This is probably the most graphically gorgeous DS game I've ever played. The soundtrack is very fitting as well, and it's not annoying, which is important since you'll be hearing a lot of it. I easily sank 20-25 hours into it before beating the game, and this one's a keeper as I expect to come back to it and tie up a few loose ends.
Overall, this is a fun RPG that is accessible to beginners but also interesting enough for experienced gamers.