Effects (β++)
Jet
Interact with the light blue flashing thing in The Nexus. Walk right until you see a building with red squids painted on it. Enter it, and follow the path until you find a jetpack. Interact with it.
1-bit
Interact with the gray metal pillars in The Nexus. Walk right until you see a stone path leading down. Go down until you see a television. Interact with it. In the White Desert, go down until you see a stone path on your left side. Go left to see a red arrow at the end of the path. Instead of going to the red arrow, go up and follow the path until you reach an area with lots of bushes. Make your way through the bushes to find a crying statue. Interact with it.
Events & noteworthy places (β++)
Squid Sky Sqraper
Interact with the light blue flashing thing in The Nexus. Walk southwest until you see a tall building. Enter it. Go up until you reach an elevator. Go up until you see a squid blocking the entrance. Talk to the squid, and answer anything when asked a question. After the squid has moved out of the way, you can enter the Squid Sky Sqraper. Enter the door to enter the exhibition. Interact with any of the machines to see different stuff.
Argon's Inspiration
Interact with the gray metal pillars in The Nexus. Walk right until you see a stone path leading down. Go up until you see a red thing. Interact with it. In the next room, interact with the red triangle. You will now see the triangle you came from, and another triangle in a seemingly unreachable area. Make your way through the maze to that triangle. Interact with it. Follow the path, and interact with the next triangle. Ignore the triangle at the top right corner of the room, and interact with the floating cube. Make your way through the teleport maze until you find an orange tile. Step on it. In the next world, go up until you find a staircase. Go down the stairs to end up in a room that resembles the Number World from Yume Nikki. In every room, you have to figure out the shape of the room, and enter the door that is in the center. In the last room, you will have to go back through the door you went through. If you enter a wrong door, you will be sent back to the previous world. If you succeed, you will end up in an isolated area in a field. You will get some dialogue congratulating your success.