very easy...

Kd6 is mate.

nice one

nice

very nice.

1. d7+ Qxd7 2. Nef6+ Kd8 3. Nxd7 Bxd7 4. Nf6 and we lose bishop on next move,but game nice. 

OMG,   so complicating,   it took me 50 seconds to do it!

why not kh6

nice puzzle

Cd6#

cool!

This was a tough one.

2. Nhf6+ is stronger because if 2. Nef6+ Kf7 3. Nxd7 gxh5.

wow... cool knights

Great puzzle. The uneven material made me think for a while. Let's have more like this.

Nice.

Nice but relatively easy.

If you mean why not 3...Kg7, good question.  I believe white still wins, but I haven't been able to see it through, and at the very least it sure looks like a better defense as it enables black's king to capture white's knight on f6 a move earlier.  The line I see would go 3...Kg7 4. Ne6+ Kxf6 5. Nxd8 Ba6.  Then what?