Did I play this game good or did my opponent just blunder repeatedly?

 I was black

I hope one of our more experienced members comment here to help you. 

I guess he was going for an italian game but then it declined, and then he screwed himself over.

Hopefully the more proficient one's will help you.

the natural knf6 should have told white there was no future in a f7 sac , i like how kna5 was played as it must have been tempting to eat the d pawn but this then allows a knf7 sac (kn no longer on f6 guarding h5 or blocking f file ) so well turned down

after h6  if knf3 e4 qe2 i think white is ok , but perhaps white still hoped for joy with the sac or didnt see qe2 to e4 after knf3

You played fine. Nxf7 was a blunder. After the blunder, you played actively and finished him off nicely.

Well considering your rating is 1100, I'd say the latter is a lot more likely than the former.

Both things. He made mistakes but you capitalized very well. 

I played this opening as white with an engine, and I took back moves when I made mistakes, and could not avoid losing in any variation I tried.  This opening for black is very good, despite being down a pawn black can get a strong attack on whites king.  Even if white does manage to castle, blacks pieces seem to dominate the game in every variation I tried as white when playing against the computer. That is why I don't play the fried liver anymore.  It's not even hard to figure out the right moves without computer aid, just develop dark squared bishop, reinforce it with a queen, move other minor pieces in for the kills, either stop white from castling or attack the castled king.  I've tried and I tried and I tried, white has no time to castle queenside, and if he does castle kingside, he's dead, if he didn't already die like in this game.

Well white didn't know fried liver very well so...

A bit of both i would say.

I'm a beginner but come on... He moves the same piece twice for no apparent reason in the opening before even coming close to development, sacks a knight...What is going on?

Maybe he was under pressure. Many players make illogical moves. Who cna say what he was thinking?! He blundered thats for sure,and you took advantage of it. Well done.