Petrov's Defense Intermediate Move Chess Puzzles

Petrov's Defense Intermediate Move refers to the key in-between move that appears in the Petrov Defense after 1.e4 e5 2.Nf3 Nf6, when Black meets White's capture on e5 with a tactical resource instead of recapturing immediately. The defining feature is Black's counterattacking move ...Nxe4 or a related tempo-gaining idea that keeps the position balanced and prevents White from winning a clean pawn.