Deepworld is an relatively new online multiplayer game. It is a 2D sandbox game with a post-apocalyptic steampunk theme. It has a hand-drawn art style. So far, you can only play on Mac and iPad. My Deepworld username is Oxidis. Anyone else playing?
A more recent screenshot: (from the Deepworld forums) In this game you can explore many different procedurally-generated worlds but there is a bit of a dash and loot mentality since raiding new worlds is the only way to get most of the rare items. Hopefully this changes when android quests are released. Anyways, this is a good game with plenty of potential, you should try it!