I know of the one in the middle on the stump-tower, the one in red spawn, and the one on the roof of the crocodile room... no clues to where the last one is.

I found it! it's on one of the spiral stair pillars in the royal-looking room.

But hitting them all doesn't do anything to the big door in the forest room...

Yeah, youve fould all of the ones I found, there must be either an order of them or a few more to find

Originally posted by True Inferno:

Yeah, youve fould all of the ones I found, there must be either an order of them or a few more to find

I decompiled the map and found out how to open the door.

Five crystals including the four we've found, with the fifth being behind a pillar at the end of the spiral-y rainbow room, you destroy all of them.

Touch every "Glaccium" (pyramid) once.

There are also ten different invisible buttons in varying locations that are in the middle of artwork on the walls, either on the Glaceon-enneagrams (the cultist-looking symbols,) or the eyeballs.

The trickiest one imo is in the same room as the Glaccium-pyramid in the dungeon area, it's the eyeball to the left of the doorway that is on the side of the room with the pit.

There's another tricky one that's in the long rainbow hallway above the crocodile room,
above the Glaceon that pushes you back if you get too close to it.

You also -have- to touch an invisible box that's surrounding that Glaceon.
- easier to do with noclip.

But after you've done that, including the crystals, pyramids, and ten symbol/eye-buttons,
the entire map will confirm your success by shaking your screen,
then you shoot the symbol above the big door in the forest room... and it opens!

Why dont you make a video about it?