Thanks for the feedback! You can teleport to the last checkpoint by pressing R , I forgot to add that to the controly, sorry.
Well, that only sort of is a bug. I wanted the player to be moved together with the moving platforms but this wasn't the case by default. So I parented the player to the moving platforms when the player is on top of them, but that caused the physics to not correctly work while being on the moving platforms. To make it short: I just disabled the player to move horizontally when on top of these platforms. Don't worry, I designed the game with this in mind and it's still doable. When holding the keys to walk/run forward and then jumping, the jump still gets accelerated forwards. If I manage to fix this issue, I'll do so in an update.
There is a purple orb on the island with the red glowing things flying around, take that and insert it in the next orb holder. A path to the red orb will be there. Take the red orb and put it somewhere. For the next orb holder to activate you'll first need the purple orb again, you can get it back from the second orb holder by pressing e on it. Insert that into the next orb holder and take the red orb to the last orb holder.
Hope that helps.