Ultima Underworld spiritual successor Underworld Ascendant has passed its crowdfunding target of $600,000. The milestone was achieved Friday, just a day after developer Otherside Entertainment held a Twitch stream calling attention to the project featuring BioShock creator Ken Levine and industry personality Adam Sessler.

“We’re humbled,” Otherside founder Paul Neurath said. “Honored to have your support. And, to be honest, a bit relieved that we actually did reach the milestone. The team is incredibly excited that we can now make the game we have so passionately wanted to make for 20 years, and do it together with you.”

The Underworld Ascendant Kickstarter campaign ends March 6. Now that the game is fully funded, Otherside has announced new stretch goals.

Should funding reach $650,000, developers will create a new region called The Underswamp. If $700,000 comes through, best-selling Dragonlance fantasy author Tracy Hickman will pen an Underworld Ascendant prequel novel. Finally, if the campaign reaches $750,000, tribal creatures known as lizardmen will be included in the final game.

Neurath, who co-founded original Underworld studio Looking Glass, launched the Kickstarter campaign for Underworld Ascendant earlier this month. The game is spiritual successor to 1993’s Ultima Underworld II, the first to create a real-time 3D texture-mapped world and player-driven sandbox gameplay that inspired games like Thief and Deus Ex.

Veteran game designer Warren Spector is acting as a creative adviser for Underworld Ascendant.