I have routed the first map of the game and defeated Golgothite's Skull in just 28 minutes! I've developed a decently reliable way to deal with the Guardian of the Antichrist, a way to cheese the Arch Angel, and a decent loadout. I now have Inside Golgothite to route and map, and I have a vague idea of how it'll pan out but only time will tell!
Stats After Defeating Golgothite's Skull
325 HP
00h28 (Note, this is in-game time, real time is unknown and most likely much longer)
25% Abilities (Double Jump, Murky Coat, Dash, Angel Wings)
18% Weapons (Skeleton Hand, Flamer, Demon Fork, Rocket Launcher, Jack Hammer, Double Barrel, and the two starter weapons)
39% Bosses (Honestly higher than I thought it would be)
Main weapon used was the flamer, it is great against everything, including the Skull