This isn't a game, but a tool to create pixel art for your game. I was frustrated with using Photoshop and other tools so I decided to make my own in HTML5. That is until, I found out about Pixen for Mac OS X, which has pretty much all the features I wanted. So, this is what I have so far at http://pixelshopapp.com
It doesn't have the functionality to create animation and it's inconvenient to create new colors but if there's enough demand, I may work to add and improve those features. It's also built in an infrastructure where I can add sharing and searching for other people's work. Again, I will work to add those features in if there is enough demand.