You must submit your game in a .swf file. Also you will need a description, instructions, and a thumbnail pic. Your game must be flash developed as well!
To submit a game, you have to create your own game and go to the submit button on the top right corner of your screen, then give the required information about your game the the site
By the way, here's thelink for submitting your game in .swf format.
Correct me if I'm wrong, but then a moderator, or someone else high ranked plays through your game to make sure it works and has nothing inapropriate. Then they will email you with the Armor Games logo to put in front of your game. Agian correct me if Im wrong.
Correction: Admins and many Mods play the game to approve of it for any violence (and/or if the game SUCKS!). Mainly Dan, Justin, and I believe Cormyn and some other programmers of the site. They will then accept/deny it, and give you a logo to put up. The testing process takes about 3-4 business days. If you don't get news within a week, you're game most likely didn't get accepted (happened to me). They don't send you an email if your game was denied (bull huh?).
Remember it has to be SWF, must contain a 100*100 size thumbnail (like a sprite perhaps), and must not contain Mochibot, Mochiads, HeyZap or other 3rd party Micro-Transaction systems.