You need to activate the mechanics before the floating platform. Press up I remember.
Those areas don't have the mechanic to press up around. I tried pressing up but it still wouldn't activate. I noticed that the platforms that you can activate have a green color on the bottom of the platorm and it tells you to press up near them. However, with the platforms that allow you to progress past the forest, there are no mechanics telling you to press up nor is it green
Sorry, I misremembered. Try go left from the floating blocks. In the end there is a stone statue of some sort of beast. Press up and something naughty would happen. Then the blocks should starting to work.