Hi, thank you for the reply!
I've already resetted the game once, and played it from the beginning, but the issue is still there... sad thing that the developer doesn't seem interested in fixing a game-breaking bug.
Ironically, I didn't know there was a reset button. I did the reset by deleting the save file.
AppData\Local\LiminalDreams\Saved\SaveGames
It may be this, or it may be the order of the switches to avoid the bug.
After reset, I didn't even get the red room and I already pressed all switches in order. Green World then the one with the snail.
Thank you for tip!
Unfortunately, that didn't work: I've cancelled the game's folder, and erased the LiminalDreams one in the AppData subfolder, in order to do a clean install. I've made through all the worlds in order, discovering all secrets, and after I got the TRAVEL button I flipped the switches in the order shown in the video (green, purple, yellow, orange), but it didn't work: still, yellow and orange are the only squares lit up.
I'll add a screenshot of my progress:
If only there was a way to contact the developer about this...
The only big difference in my playthrough was that I pressed the switches as I was normally completing each level, I didn't wait for the red room to press them.
Except this which may be the reason, there was still ONE little detail, while playing in the exact order in the image:
I literally forgot about the scroll in the green world, and I didn't collect it, not even after getting 4 stars in the secret blue world.
You can apparently get in the blue world without the scrolls, though I still don't surely know if I have completed the game or not.