[WIP] Saved by the cake
Sorry Lohitrad, I'm just confused and a little scared about whether or not this is going to be a common issue. I don't want to have to make it too obvious; I have an idea though.
There are a number of problems with this map in it's current state:
Misaligned textures.
The 1st puzzle can be screwed up to the point of needing to restart the game.
The glowing red bar is not a known convention and needs to be taught - also, it looks bad.
All the glass you have need to have plastic brackets as in the official game - right now it looks bad.
The point of a WCC is that it is a companion and should not be killed to easily - I would let the player keep the WCC and use it as a solution to your 2nd puzzle (which by the way NEEDS to be changed).
The whole 'L-block' thing doesn't follow any sort of convention that even remotely resembles anything from the game and therefore needs to be taught or removed from the game.
There are probably some other things too. It's a decent start but needs a lot of refinement.
P.S. You should watch your tone when responding to peoples posts - they don't have to test your map and give feedback.
Do we need a mediator for criticism now? ^^
From what I've read so far you have an L-shaped object that can be interacted with in some way. Remember how in Portal you would find these little white squares which showed you stuff relevant to nearby game elements? For example, by a ball launcher you would find a white square with a man getting hit by the orb, an a warning. These were also used as instructions. I suggest creating a similar sign and placing it near you L-shaped object, as those little white squares are a knows Portal element and would effectivly convey the message to players.
You know what? Map making is obviously not my strong suit. I have no idea how I'm supposed to "teach" the player anything, so I'm going to have to give up on this map. I'll keep everything you guys said in mind if I make a new one. Thank you all.
As long as you don't give to mapping entirly. Don't feel bad. All mapers who have mapped a certain ammount of time come across maps that just don't work and have to start over, and I know, it feels pretty hopeless, but it's really not your fault. I'm sure this map would fit nicely in a certain game. Just not Portal. 
Try again. Please.
Your post has been deleted and you have been issued a warning. -Espen180
Yeah Helix, don't give up. I honestly believe you have everything it takes to make a fantastic map maker.
I just finished the map, and I loved the third chamber. Though I didn't intend on getting there.
Hell, I didn't even know there was more after the cake until I read the download description from the upload. I hadn't made it to an elevator, so it wasn't over.
for those of you wondering how to get to the third chamber:
If you were to continue work on this map, there really are only a few things that you'd need to do in order for me to really like it.
Move the portalable ceiling tile a little closer to the button opening.
Make the button opening a little larger.
Give some sort of diagram as to the L block, or change the way the L block is introduced. Perhaps a cube dispencer dispencing the wrong item? I'm assuming that can be done.
Give more hints on how to get to the third chamber.
Improve the lighting in the cake area and in the area you drop to shortly before the third chamber. Way too dark.
Once those are fixed, it would be great. Also, I loved the line for if/when you emancipate the turret.
Okay, I just played through this map. My first thoughts were:
Room 1: It took me a few deaths to realise what the puzzle was, and why I was dying. This could have been made more obvious by using some kind of energy field or something, instead of just a red line (I didn't actually read your first post, as I wanted to play it with no preconceptions).
The puzzle itself was ok, and I eventually realised that the
Room 2: (By this I mean the connecting hallway.) The main problem I have with this room is the only object in it, the emancipation field.
The emancipation field is fine for stopping storage cubes being taken further into levels than desired, but the WCC deserves a more grand death than that.
I actually thought that since you had given us a companion cube as opposed to a storage cube, I had to somehow bypass that field, as the companion cube is something GLaDOS thinks humans should be attached to, and therefore makes them consciously kill it, as opposed to leaving it behind, or simply taking it into an emancipation field.
I hope you see my point in that last paragraph, that the companion cube's iconic status means that any "euphanising" should be forced, and more grand.
Room 3: What the hell? lol. I had to come and read this very thread to find out what to do here, and even then I was like "that's stupid". (please don't take offense at that). I believe Lorithad has said most of what i also thought about that particular puzzle.
My suggestion would be, rather than
Also, about the
Last section: On the left hand side of the
Please take this post as constructive criticism, as this has the potential to be a good map. Also, this is just my opinion, others may vary 
Hehe, glad I didn't read through this thread before trying the map. The first room I found cool and satisfying.
The second room I was as clueless as anybody in this thread.
I spent quite some time trying to figure out how to get my WCC through the emancipation grid, but that didn't work of course.
After the second room I only just had time to think "oh fck" before being "saved by the cake". Is that the end of the level? I couldn't find anywhere else to go.
EDIT: Don't quit please. This map demonstrated some true innovation and I'd love to see it finished. It just needs some polish on the whole "introducing the player to new gimmicks" front to be great!