Vampire Survivors

Hoo boy, this is a fun one.

You'll need to play a non-special character (so no Red Deaths) and survive in the new map called 'Moongolow' for 15 minutes. This map gives you all passives right off the bat on the ground.

After surviving for 15 minutes - the game will freak out, you'll get some strange lettering on the screen, then get sent to a secret level with a long hallway.

All of your items will poof and you'll revert back to the 'basic character'. Don't bother trying to fight the mobs, just run. You won't get any experience so no levelling. Try to run along the lamps so you can hopefully pick up some floor chicken along the way. At the end, you'll get a rosary that will clear the screen of monsters and open a trippy pathway across to the yellow sign item itself.

If you die, you'll get the opportunity to replay it with any non special character. I've found 'Poe' to be the easiest to use, the garlic kills most of the bats in there and lets you collect floor chickens will running.

The achievement itself is a bit bugged, you'll need to go to your collection screen and highlight it to get it to tick.