The dark knight attack :)

heh nice combination with the queen and knight. very clever

Shouldn't tal castle on 13?

This should be on tactics trainer with on move 15.

13.b3?? is the losing move

If instead 13.0-0 and the result is unclear. Interesting lines develop after this point.  After 13... Nb4 14. Qb1  Qa6 15. Na4? is a losing mistake although white is pretty much hopeless as can be seen from the diagram below :

15.Na4? [15.Ne5 d5 16.Ne2–+ Nd7 17.Nxd7 Nd3+ 18.Qxd3 Slightly better than 15.Na4 Although still -2.8 according to Fritz]

Let's go back to a few moves before. White's biggest mistake is 13.b3??  Only as I analyse now do I see what a bad move that was. Let us examine some other possible white moves.