Area: World C-1

1:) Glitchy Room with Elohim:

This one is so hard to miss It’s certainly more part of the story than an Easter Egg. But I’ll add it anyway to avoid any “you missed something obvious” talk :3.
Looking at the entrance of the puzzle “The Conservatory”, follow the right wall of this puzzle. You will soon hear and see a glitchy square on the ground. Just walk on it.

1:) Gnaar Statue:

On this map you can find 10 parts of a Gnaar statue hidden a bit everywhere outside the puzzles areas. There is a pedestal on which you can rebuild it for a little surprise.
I’ll eventually write a full guide for this but meanwhile you should look at this video guide from Tengu Drop:

Area: World C-2

1:) Fork Parker & Money:

From the teleporter, go straight ahead into the red door of the chapel looking building. It’s not solid.

2:) Telescope & King Gnaar:

Inside the “Rapunzel” puzzle, if you go up the ladder and turn around, you can get a key on the left gargoyle.
From here you need to bring up a platform and a Hexahedron. Then record youself first holding the platform next to the box (so you can jump on it) then jump on the cube to get high enough to reach the telescope.

Area: World C-3

1:) Gandalf Gnaar… Gnaardalf?:

In the “Weathertop” puzzle, head directly to the cliff edge opposite of the entrance and look down.

2:) Serious Sam in Carbonite:

Go through the purple field just to the right of the previous easter egg. Here jump down from the cliff edge to small ledge with a tree. Then follow the ledge. Tengu Drop made a video on how to get there:

3:) Snowman:

In the “Jammer Quarantine” puzzle, it’s behind the quarantined jammer on the promontory.
I reached it using the jetpack but maybe it’s also possible using an Hexahedron.
Don’t forget to fix up his fallen button for a surprise.

4:) Jetpack:

To be able to get this you need to finish every puzzle in this level and get the star. If you don’t the path will be closed. In the puzzle “Big Stairs, Little Stairs”, go straight ahead of the entrance and to the cliff edge on the right of the blue laser emitter. Here if you jump down carefully you will reach a cave.

5:) Frozen Gnaar Cave:

To get in there you need to fly below the entrance of the “Big Stairs, Little Stairs” puzzle using the jetpack. The puzzle to get inside won’t be hard to solve if you got that far. You need: 3 Jammers, 2 Hexahedrons, 1 Fan, 1 Connector and a Red laser from the “Three Little Connectors… and a Fan” puzzle.

Area: World C-4

1:) Pictures of the Developers:

Before the “Stables” puzzle, jump on one of the left gargoyles and then on the wall.
The pictures are on the balcony, you can get up there using the “Casual” or the “Hardcore” way.

World C-6

1:) Diamond Sword from Minecraft:

In the puzzle “Circumlocution”, in the area where the Tetromino is you can find a gap in the wall hidden by some trees. This sword can be used to slash some vines behind the teleporter. It will reveal a QR code with a message that translate to “you are not here”. It’s a reference to Antichamber.

Area: World C-7

1:) Another Snowman:

In the puzzle “Carrier Pigeons”, it’s in the area behind the altar. You can get there by stacking three hexahedron and jumping on it from the nearest platform.