Hello folks. Below is a text version of the solution as well as a timestamped video for all 5 Achievements in Title Update 3.
For Secret Crystal 1, we need to play Level 5. Levels unlock as you play the game, so you'll need to get through the previous levels to get here.
Start by going left and moving the center of the 3 blocks down, and pushing the right-most of the 3 blocks onto the red button. This opens a gate to the Northeast. Push the block that was locked in here into the blue portal, then push the box you moved onto the red button into the blue portal. Now push the other two boxes into the green portal. This causes the boxes to hit each other and explode, opening the path to the left. At the very top of this new area is Secret Crystal 1.
Level 5 starts at 1:08