Green mushroom door challenge rooms?

[Rev-Up]

I have beaten the game multiple times but I can't figure out how to open a specific challenge area that I encounter about once every 20 runs.

It's a closed green door that leads to some platforms with monsters and a chest at the end. On the final platform there's a golden mushroom door that's also closed (this probably opens once the room is finished).

Does anyone know how to open these doors? I thought maybe they could be timed doors that require you to speed run like in Dead Cells, but I don't see any time indicator. Another idea is that maybe you have to be full HP or have not taken any damage during the entire run?

Thanks.

[MrBendiix]

Is it the one that appear in world 1?

[Rev-Up]

Yes, I think I've only seen it in the first zone.

[chsr357]

If we're both thinking about the same thing, then I believe those doors only appear when you pick swamp as the 1st biome or at least, that's the only area I've seen it.

There is usually a hidden path near the 1st mushroom door that has the same color switch. Step on the switch, then go back to where the door was. Get chest, step on 2nd switch, and exit back to normal path.

[Rev-Up]

Originally posted by chsr357:

If we're both thinking about the same thing, then I believe those doors only appear when you pick swamp as the 1st biome or at least, that's the only area I've seen it.

There is usually a hidden path near the 1st mushroom door that has the same color switch. Step on the switch, then go back to where the door was. Get chest, step on 2nd switch, and exit back to normal path.

That sounds like the same thing indeed. I guess I haven't searched for hidden paths near the door hard enough but I'll try that next time.

Thanks!