Get Lost in A Witch's Tale
It plays like Final Fantasy X in the sense that you have many elements at your disposal and that you have many dolls to choose from. Each doll has a base element, but most learn other elements.
There are, however, a couple things that I didn't like about the game, like the fact that there is no journal of enemies and their elements. You will have to remember the element that you used with the most power on a certain enemy, which is bad for a fact that many enemies are the same with different color schemes and elements.
The game is also very easy once you are past the first world, which for some can be offputting, but for others great. I personally loved it, as most games that I get I die a lot and throttle the controller or DS in anger.
Although I am only at level 23, I would assume that since my spells levelled up when I hit level 20 and spells have 5 levels that every 20 levels your spells go up a level. At somewhat random points in your dolls leveling up, they get new spells or upgraded versions of a spell.
You control everything with the stylus. You drag and drop spells to the enemies slot to use it against them, and each time you complete a level you get a version of a spell that is called Ancient Magic and costs 99 MP and is very powerful. You start off with Expa Abyss before you even start fighting. There is one problem about this, though. There is no tutorial when you start out. In Shadow Town, a sort of hub where you can repair your dolls, exchange items (very much like synthesis in Kingdom Hearts games) and regain HP and MP, there is a shadow person on the bottom part of the town who gives you a tutorial of sorts. If you don't talk to him you are essentially thrown into the action. To get ancient magic, you have to gain a Sigil from the elements respective Princess, which you do by completing the (somewhat, although not really) repetitive world. To use it, you drag the element you want to use into the middle of the scroller. When it is your turn you draw the rune.
Overall, A Witch's Tale is a great game with great music and gameplay.