That is funny because I tested that before publishing and it never worked - the cube would fizzle out for no reason (must have been a glitch) so I let it go. However, I just published an amended version of the map that should take care of it. Basically, I just added a box of grated walls instead of a single grate on the upper wall. Now if you put a portal below the cube it will have to fall into that box of grates or to where the repulsion gel wall is located and you shouldn't be able to get it out.

If you have time I would appreciate it if you could try that same part again and see if you can still exploit it. Many thanks for pointing it out!

I just shoot my portal under the reflex cube he just fall in front of me, after from the main room i can get in and grab the reflex cube and the ball.

I will have to play through it again to see how you did that. I assume you got the reflector cube out of the second area - is that right? If so, how did you manage it? I tested that quite a bit but could never find a way to get it out - the obvious way to do it would be to use portals from inside/outside the room but when I did that during testing the cube would fizzle out.

I got back into the control room with 3 cube and 1 ball.

Thanks for the feedback. To your point about adding an extra cube at the end, that was part of the challenge. I assume you figured out how to get back into the "control room" with the last cube, though?

Fune puzzle the first jump with faith plate is a bit annoying you need to get it perfect or you die. I add a extra cube at the end.