Let me start by saying that mScribble isn't a game per say. The level of control you have over it is very basic and there are no goals, specific directions, or much of anything that can be referred to as “gameplay.” More so than a game, it would better be characterized as a sort of musical lava lamp. It can be cool to mess with it and see what happens, but there isn't much to mScribble. While playing around with it, the app felt less like a full product and more like a tech demo of a feature that would be included in a future game. As such, mScribble does not have the lasting value of some other music-based apps on the market. I found it to be an interesting toy for about five minutes, at which point I felt that I had seen all it had to offer. With continued play that proved to be the case as I didn't feel like I was learning any more about how to play the game or divulging whatever hidden depth it might have.
Upon starting the app, you are presented with a list of ten options to customize your mScribble experience. The first nine are something similar to “levels” which consist of slightly different looping beats and a basic animation that plays in the background. The tenth being a brief tutorial on how to play. Aside from that, there are four flute-like tones to choose from that differ from each other only in pitch and change in volume level as you scribble (get it?) around the screen with your finger. The volume of the musical tone changes randomly as you move your finger around the screen so there is no way to actively control how the music sounds other then to make it change. There is no multi-touch support so this minor change to a basic musical beat equates to the entirety of mScribble.
There is one other way to influence what happens in the app, and that feature is my biggest problem with it. Double-tapping the far lower-left corner of the screen reverts the app back to its main menu, or at least that seems to be the intent. Roughly every third time I tried this, the app crashed and I was booted out of it. This seems to be happening more and more with apps since the release of OS4 and is definitely not an issue exclusive to mScribble. Still, the consistent locking up of a paid app is not something an iPhone/iPad/iTouch user can be expected to tolerate and this problem would have to be solved via update before I can fully recommend that anyone purchase mScribble.
Freezing aside, the game is a neat toy that I would recommend for small children who need something uncomplicated to play with. For adults, it is something that can prove to be passively entertaining in short spurts, but not much else. I have certainly shelled out $.99 for worse, but there are better musical alternatives in the app store if you are looking for something to entertain you for any length of time.