To be honest, I didn't like Order of Shadows, nor I liked its music.
But there are some things I liked about it...
The first stage theme has potential to make a good track, but I find it lacking in composition. The chord progression lacks emotion to what it makes an emotional and powerful Castlevania first stage theme. But it has the potential. The composers were, according to the review from this site, a bunch of newcomers, or something like that

So, it's understandable.
The final level theme is very beautiful, but I don't know if it's an actual original theme or a classical one. One way or the other, it was the highest point of my experience with the game.
About the gameplay, I couldn't play it with a phone. I acquired a phone exclusively for a single Castlevania game, since my previous phone didn't supported it. And I was highly disappointed. But I see potential for (like others said) a remake, with better gameplay and more levels.
I wasn't able to finish the game (I'm not good playing with numerals), so I ended up emulating it a few days after buying the new phone. I beat the game, and I really didn't like it, but I don't know how they could have make it better with the mobile technology of that times.
About the Sorrow mobile games, taking into account that they are mobile versions of great NDS games, I think they fared pretty well. You have to take them for what they are and not compare them to their NDS counterparts.
And last, about Order of Shadows being better than Mirror of Fate... I don't want to create discussion, but I think that's going a little too far. Mirror of Fate may not be what I expect from Castlevania, but it is better than Lords of Shadow in my opinion, and it has some redeeming elements, at least to my tastes (nice backgrounds and details, some stages, nods to past games, and a touching story), and that's a lot more about what I can say about Order of Shadows.
I think Mirror of Fate is a game way, way better than Order of Shadows.
Although, I find the comparison a little unfair. One is for an 8th generation portable console, and the other for old java cellphones.
I'd like to see full remake of Order of Shadows, if possible for 3DS, and only then the comparison would be fair (in that case, I think I'd be more inclined to my traditional Castlevania type of game, but that's only hypothetical so far).
Sorry for the long post.
Edit: Changed "I think Mirror of Fate is a game way, way better than Mirror of Fate" for "I think Mirror of Fate is a game way, way better than Order of Shadows".
I used the same name twice in the phrase
