Nabeel Hyatt, general manager at Zynga's Boston studio and former CEO/founder of Conduit Labs, has resigned from the social game developer to join venture fund Spark Capital. Hyatt oversaw the launch of Zynga Boston's Adventure World - An Indiana Jones Game last September, and while the gamehas managed to hold onto several million players since its debut, it's one of the least successful titles Zynga has put out recently. Adventure World, which is a departure from most Zynga titles due to its focus on storytelling and puzzle-solving, currently has 5.8 million monthly active players on Facebook, according to figures from tracking site AppData. Though that's more than most titles on the social network, other recently released Zynga games boast much higher numbers, like November's CastleVille with 30.1 million monthly users, and January's Hidden Chronicles with 26.9 million monthly users. Hyatt has served as the Boston studio's GM for about a year and a half, since Zynga acquired Cambridge-based social game developer Conduit Labs. He founded Conduit Labs in 2007, and helped the company release music-based games like Music Pets. He explained on his blog that he's leaving Zynga because he wants to work more with startups at Spark Capital: "For me it felt like time to see if I could shift my focus from building a single company to impacting the broader ecosystem."