analysis says blunder

en.lichess.org/8zBkvuCF/black

Look @ this match ... move 15 says blunder. I did not need the extra move or king safety to castle. Him snatching the rook didn't matter. If I castled my rook could of captured his bishop and delayed mate.

I had set a trap for my opponent to capture my rook, next sequence of moves was mate. Why would the analysis say it was a blunder on my behalf.

It's a blunder since he can just play Nb5, then sidestep the check, and then win an exchange.

@x86

Its almost a nice trap except in this case it doesn't quite work.

After .. Ng4 Bxd8 Bxh2+, white doesn't have to play Nxh2. White can move the King to h1 and he wins an exchange.