[spoiler] What is this?

I've finally explored some secret area in Knytt and I found this (picture attached bellow).
I noticed, that I can jump higher, but I still have some questions:
Will the ability to jump higher last for all game ?
Are there more of these ? Do they have different functions ?
Does pressing L or G influences it's function ?

You found one of the secrets! There are many more secrets. This one lasts until you restart.

LG, which stands for Low Gravity makes you able to jump higher. You activate it by pressing both keys at the same time.

Thank you.