Well. I have been playing Qbeh-1 for quite a while now. However, I do not understand how to get up the the "3rd level" using the 3 green cubes in very beginning. Maybe, I am not good enough at jumping... Is there a trick?

I had no problems finding my way, the way was always clear for me.
Like evrytime fantastic look and gameplay.

I think the way is unclear after raising that door. You might want to update the architecture, make a tunnel there to the exit, maybe hide the door and focus the player's attention on the exit path with lights, etc. I originally thought I had to drop back down beside the raised door, not go outside and by the save stone. But I figured it out eventually.

I got stuck temporarily at the same door that Ellie had problems on.
I managed to find a way but it feels like there should have been a more easy way.
I used two green cubes to get into the door which was kind of wonky.

But overall a very cool level, good job! The five red cubes were a bit unnecessary though, two or maybe even one would have sufficed.

I played through 3 times before publishing I think, I never had a problem with the 2nd door.

I found a way to finish. The only difficult part was collecting the last blue cube; I had to guess where the ice blocks were and try to figure out where I was going. But a fun level!

I don't understand. I have to stand on a cube to jump to the ledge, but I cannot stand on a blue cube because then I cannot unlock the door. Play through it and see if you can get through. It is always a good idea to do a play through before publishing or uploading changes; you don't want players getting stuck. :)

Second cube door, I did not plan it as I had to use the 2 blue cubes, originally was a green cube, but you can just grab blue cube.

http://images.akamai.steamusercontent.com/ugc/305485758889967803/F4FED7385EB6B97157EE02E3622EED8532D5C773/
I cannot get into the 2-cube door that is upstairs. I need at least one block or a way to use the blue cube and then unlock the door. Otherwise, I like the level - any I have to say that you are producing levels so fast! :) Keep building - you will really learn a lot and make even better levels. Have you added a secret area yet in any levels?