Perhaps to take the game out of well-trodden lines? 2...Nc6 is more often played, because it is better. Why? It protects the e-pawn (admittedly not actually attacked at the moment) and brings the knight closer to the centre. 2...Nf6 would have been OK, too, attacking White's e-pawn (though that is defended by the White knight). The other downside of 2...Na3 in this opening I'll mention in my next comment.

Well played. But White could equally well have played 3.Bxa6, doubling and isolating Black pawns on the a-file.

Instead, 4.Nxe5 might have been worth a look.

'Castle early and castle often,' was the half-joking epigram of World Champion Emanuel Lasker. In 'fast' openings like this, it is very good advice! Now was a very good time to castle. White is still 3 moves away from castling.

Protecting the hanging e-pawn at last. Game should be fairly level here, I think.

Good spot for the light-square bishop. The a6-knight is a bit out of the play ('off side'), but otherwise Black's position is fine. White's isn't bad, either, but he's fallen rather behind in development. That could be telling, unless he hurries up and gets on with it.

In my view, not a very good choice, owing to Black's reply. Probably better would have been Be3 or Bd2. Or maybe 8.b4 followed by 9.Bb2.

Unsound. Probably best, after having provoked the h-pawn's advance, would have been to retreat to h4 or e3 or d2.

There was no need for this. 10...Bb6 would have been fine. Black would have kept the extra piece and had a winning game. +++++++++++++ Having said that, this 'return sacrifice' does have quite a bit going for it. See my next comment.