very neat!
Checkmate with just 1 knight!
First I would like to say congrats! Now, unfortunately, I must critisize. Your opponent blundered, badly! Also, he made a massive mistake by weakening f6 with 6... g5? And finally, I cannot commend 3. Be3?!, whic blocks the e-pawn and thus your development.
I don't castle a lot when I use this opening. That's why I leave the central pawns near my king. I use them as shields.

I believe that's called a "smothered mate".
A smothered mate is one in which the knight checkmates the king when the king is surrounded by pieces and has nowhere to move whatsoever. This was not a smothered mate; the square d7 was open for a move by the king. Had the light-square bishop for Black been on d7, then yes it would have been a true smothered mate.
Here is the coolest checkmate I've ever done!
I only used 1 knight!
I was white.