Fastest Middlegame Ever

Ok, maybe not ever, but pretty quick.  I made 7 captures in 8 moves in the middlegame to quickly go to the endgame.  Even though I was the exchange down, I had two extra pawns and a fairly easy endgame win.

I'm still not sure what motivated me to play 15. ... Nxd2.  Again, the only thing I can think is that I miscalculated.  On the other hand, given that I had a ton of time left on my clock, and the calculation wasn't all that difficult, I'm not so sure.  Maybe I just thought the g2 pawn was valuable enough to lose the exchange for.  Who knows?  In any case, it led to a good engame for me.