Once you beat the boss, the stage does return to normal.
Beating that boss unlocks a fancy new relic: the Great Gospel.
It gives the option to keep levelling up weapons past their limit, which I imagine grows ridiculous?

I’ll have to play with that and see.
A new Arcana perk is in to find too.
And apparently the update snuck inyet another secret character.

Given how many surprises and secrets Vampire Survivors slips in, I do expect it to add more.
In ourVampire Survivors early access reviewback in January, Matt Cox called it “an unquestionably compulsive treat”.
Hard to believe it was five months ago that the game had only two levels.
It was tiny then!
It’s grown so fast!
“I’ve read many reviews of the game,” lead developer Luca Galantetold usa few months back.