Wow thanks for the mountain of feedback! 
A lot of this is already implemented in the game. The mushrooms are actually fairly low res for next gen but they are also loded so they only load that when you are close enough.
I do need to fix the particles just popping out, I have added it to my list
The grass already has wind applied to it using both sine waves, panning textures and wind. I really need to do a new video to show it all off 
I need to do more rock variations, added to the list.
I am not a fan of UE4 translucency on meshes, It sorts really badly so I try to avoid it where possible.
I will upgrade to 4.7 asap. Just need to check its compatible with the PS4.
Thanks again for all the feedback