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?
(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!