With the centre dominated by his strong knight, White launches a kingside attack.
Heading for f8-g6-h4 with kingside pressure. Besides, on g6 the knight will be useful in eyeing the f4-pawn.
Leaving the king under a cloud. Preferable was 6.Qxf6 Rxf6 7.Nd1 heading for e3.
Both 3...Nxe4? 4.Nf5 and 3...Qxe4? 4.Qxe4 Nxe4 5.Nd5 fail tactically for Black.