You can only submit games that you made yourself, but if you'd like to see a game on here you can try mentioning it in the "what games do you want to see on AG" thread. Hopefully an admin will read your post and if he thinks the game could belong here too he'll try to contact the developer.
What gaboloth said -- but I'd also add that you should try contacting the developer of the game yourself and ask him/her to submit their game to Armor Games.
