that what i meant post #18

There are lots of variation of chess games like this,I have asked in the past for chess.com to put them all on here but so far,they have put none on here.

yeah it is checkmate but it isn't a legal position

You sure about that?

how do the pawns get on the other side?

By moving forward.

How can you think that's a legal position >_<

And... never mind.

This is as close as you can get to making it a legal position:

It is not legal in standard chess,it is legal in upside down chess.

The pawns promote by 1)moving a knight out of the way and 2)moving the pawn  to your own back row.

Alice chess is very interesting, a piece moved on board one, transposes to equivalent square on board two.Causes some serious thinking, I can tell you.

Benedict chess is another good one,pieces captured change to your colour and you can place them, any where legal on the board,except to cause check or checkmate if I remember right.

So this is an example of transfer chess/bughouse

not really you play both boards, so no handing pieces over, they just go to the other board,  same square you moved to on first board,and you can switch between boards and move on either one,checkmate on either board ends game,but if you can move king to safety it goes to alternate board but must not land in check. 

Benedict chess only uses one board so don't need partner for second board.

This game could get very interesting very quickly

4.exd6

Basically he had the pawns at the opponen's territory, since the first move was marked as Nf6 and not Nf3.

But that isn't the best continuation to this opening!

I guess, I was more planning around the fact that Ng4 threatens mate in the next move as per the OP. Was just a throw away comment anyway