Level 4 is impossible, it says at the start.
hahah nah it's not impossible xD
first you put the portals like that:
when you pass the blue, instantly, you put the portals like this:
then, you will jump between the two portals, so you have time to put here the other portal that will lead you to the isolated platform:
aaaaand then... maybe someone can help you to press the button ;)
PD: Thank you for the feedback and for playing! I really appreciate it ^^