I finally got someone to let me borrow their iphone to play. (I was being an idiot while playing and decided to hold the phone such that my finger was crushed by my headphones, so one of my fingers hurt right now)
Love the polish of the interface, esp the intro screen.
About the songs, there is a sort of lack of things in either extreme imo. My friend, even after completing the tutorial thought that even easy mode was a little hard (She could do hitchhiker but sunrise's easy diff was a little hard for her). It would be nice if there was maybe something even easier? The other complaint I got from her was the lack of a fast song in the free song pack (I don't know if she would have been able to play it), but I think she would have enjoyed it more if there was something a bit faster paced.
On my end, I thought the extreme diffs that came free were a little too easy... After getting used to the interface (took about 15 tries), I could beat both of them (with Cs, probably a given knowing my horrible accuracy on standard). On another note, I was also a little annoyed at seeing a note partially overlapped by the hp bar in hitchiker (forgot which difficulty).
Oh well afterward, my friend took her phone back and uninstalled the game (I think she only got it for me to play T_T). For myself it was fun for the short period it lasted. I am not sure how often I would play if I actually had an iOS device, but I do frequently play osu!droid to burn time. As a result, I can see myself playing casually, but I probably will need to try some of the harder maps to satisfy my need for speed.
I'll have to go in IRC sometime though
(this is actually more often the reason behind a problem, than there actually being a real problem). 
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