Maybe add in a few more "!" so they know your serious. All caps is great but make sure to write it in L33T or they might think you're just a kid.

Tell them about how all your friends and teddy bears liked the game as well.

Also make deragatory remarks about their sexuality using only 3 letters if they don't publish your game.

And don't show screen shots or demos, just tell them it will look great when it's done.