The very last level is too hard as compared to the previous levels. I think one of the reasons for that is that you have all the stalactites of the same type and the speed at which they fall is too high; the part of the boss battle where they turn into the icicles / freeze stalactites is especially hard since if one hits you, you no longer have the necessary speed (even at max Speed level) to avoid the rest, resulting in a stunlock unless you're really lucky.
Also, at least some of the medals still aren't working (Evasive, Still Can't Crush This).