This map uses a mechanic from an old map I created called emancipated polarity. What ever color portal is in front of the funnel, that's the color it turns. It also has a red fizzler that will act as a mid-air one way button
EDIT- thank you sicklebrick for reminding me about the external thingy.

Click here to download Portalarity

Looks interesting but feels broken. You can't put a portal in front of the second funnel at all. Also when I bunnyhopped down to the middle platform I was stuck because of that.

If all so far is intended I will take another look but strafe jumping pack to the beginning felt wierd. Also note that you can skip the first part by just strafe jumping to the other portal gun.