It's good, especially for your first AMV. I like how when one singer sings you show Roxas's point of view, and when the other sings you show Axel's. Try to fit in some effects, like fades, greyscale or sepia tone. Too many effects are distracting, but if you have the right amount they make it more interesting. Sometimes when the clips change it's not very smooth, but that's WMM, I know it takes a while to learn how to control that. Overall, quite good for your first one. You used a good variety of clips. :]
that's a great first vid^^ I do agree with Luna in saying that some of the transitions could be a little smoother. Though I'd say master timeing and stuff before you try playing with effects too much.