Steal Princess' gameplay is okay. Not great, not terrible, just right in the middle with a lot of annoying parts that keep it from ever truly shining. For one, the game world is set up in stages and each must be cleared to make it to the next. Now don't get me wrong. These aren't platformer style stages. These are small rooms with simple puzzle stages, similar to Adventures of Lolo on the NES. Only these puzzles aren't quite as good.
Also, the game world is in the isometric perspective, putting everything at a slant that makes it look 3D. This was a nice trick back in the SNES/Genesis days, but now it is just downright annoying. Controlling Anise as she moves around is difficult , even when the game provides you with two control schemes, touch screen or buttons. The touch screen controls are unresponsive and the buttons are slow and blocky.
Puzzle wise, Steal Princess is similar to the dungeons in Avalon Code. You have a room that needs to be cleared with certain conditions (you always have to find the key to unlock a door). Anise only wields a whip, but she can pick up other weapons and use them to defeat demons. If only picking up items were easier and more intuitive it won't be so annoying. There really isn't much of a puzzle to most of the rooms, and you have 150 to get through before the ending. Oh, and each room is rated with a medal on how fast you can get through it. I suppose this is for folks who want to play the rooms again and again. I don't know who would like to, though.
As an added bonus to finishing the game, you can create your own levels. Yeah, they really were going old school with the design in Steal Princess. A level designer? Like Load Runner? Cool! I don't see why that would even be an added bonus. I like designing levels, but having to get through the entire game to be able to do so? Not worth it.