i think it was less than 10 attempts, the run was probably 30-40 minutes long. i got close once but got destroyed by the tiny guys with swords before i knew they existed. i specialized into the shield gun because in my experience you can't get very far without relying on it. i think i was lucky to find the Skarl early, and i don't think i would have been able to beat the final boss if i wasn't carrying the Faust