New doors after boss battles

[RILDOODTYRONE]

Can someone explain what the new rooms after boxx battles are. One requires a key, one you gotta bomb to get through, and one is a spike door that hurts you before letting you in. Gone through them a few times and looks like I land in a much more difficult dimension. Dont know the purpose though, or where it leads

[jayhena]

it's an alternate path, there's an ending and a special boss if you do precise stuff in downpour 2, mines 2 and mausoleum 2.

[Hate Army]

Not to be an ♥♥♥♥♥♥♥, but part of the charm of a game like Isaac is the discovery process, trial and error.

If you're really determined to spoil yourself, try looking up the following terms on the BoI wiki: Downpour, Dross, Mausoleum, Mines, Gehenna, Corpse. These are the names of the new areas/alternate path through the game.

[RILDOODTYRONE]

Thanks, I will spoil myself. Love the game, but I like knowing what Im supposed to do in a game like Isaac.