I really like the whole game, and during my playthrough I recorded for YouTube, I accidently found a Bug which can halt your game progress and you may have to start the whole chapter from the beginning again. So here is the soultion to if (until it is fixed)

Its in chapter 3 after you get the rope.

You take the rope, swing across the first gap and land on the little island outside the cave. Then you take the next ropeswing to the next platform. On this Platform is a Door which you have to open to progress.

After you have taken your first swing, instead of progressing the level, swing back and fall into the water. The respawn is on the platform outside the cave. You now progress the level as usual and take the second swing. But about 5 to 10 meters infront of the Door the hitbox for the floor just ends and you fall into nothingness. The whole floor from this point on is there, but you can walk through.

Swing back to the Platform where you got the Rope. Then Start progressing normal through the level.