Not sure which game you are referring to, there are two on your page... I tried Alien Games and I couldn't even get past the intro text, no keyboard input seems to do anything. Bubble escape works but, it is pretty basic in terms of gameplay, just dodging the same projectile over and over. It is fine for someone learning game development but just doesn't offer much to the player.
I would focus on just making something fun. Building a community around a game requires several things, first of all it needs to be a game that catches a lot of people's attention and that they want to keep playing for more than one session. Then there would have to be some reason for players to interact with each other in relation to the game. For example, people like to talk about different character builds for RPGs. They are not going to talk about how they got a high score in bubble escape, as there's one and only one strategy involved. You can't really force a community - it will build itself if people like the game enough and have something to connect with each other.