[SP] Nightscape
A seemingly easy puzzle in the destroyed theme. Thanks to Vector for playtesting. Please use the workshop page to rate the map if you want to, since the in-map rating dialog box (which shows up on entering the exit elevator) is not working for some reason.
Note that there is a solution which makes physical sense, and one of the floor buttons is -supposed- to malfunction. Also, this is my first attempt at the overgrown theme, so please let me know if something looks off or jarring and I will try to fix it.
Nice little puzzle 
I think I found a diffrent solution.
. 
I will test that in the new version ( if there is one)I like your first attempt on the destroyed theme. But it kinda feels too constructed. Not natural. Maybe its because of the dark lightening.
@marKiu: "
I will test that in the new version ( if there is one)
As for the aesthetic side, I'm trying to make it look like night-time. I've tried to recreate an eerie atmosphere with slightly suffocating visuals, with a kind of "I'm afraid of the dark" vibe, like in horror games/movies. This is because all destroyed maps that I've played so far are set in early morning/forenoon. In fact I'm even thinking of adding fog in the next update.
With that said, do you suggest increasing the lighting? I was sort of reluctant to do so for otherwise it wouldn't look like night-time.
Hmmm... I'm far away from average when it comes to stuff like this in hammer... so I dont really know how to put it into practice but it would be nice if we could see the sky. In the last map from the campaign you could see the moon... maybe a little hole in the ceiling with moon and stars would be nice. Now it looks more like a very dark room. 
The moon could cast shadows and a visible lightbeam inside the room with glowing particles in it..like fireflies. ( I'm pretty sure this effect is used in tunnels in a cs source map de_dust2)
Otherwise I'd suggest a slightly blue color for the enviroment and maybe some orange lights?
Another thing I noticed is that the scrap on the floor is brighter than the walls. It somehow looks like its unaffected by the lighting. ( Is it just me?)
About the architecture... I noticed that you added those glasswalls near the portable surfaces to prevent the player from shooting a portal from the exit area. In my opinion it would look more natural if the player would not be able to shoot a portal because of the architectonic dimensioning of the room. Same for the cube dropper button that is caged between glasswalls and a panel. These elements create an agitated mood in my opinion. Maybe you just add another little room for the button. I noticed in many destroyed theme maps that it's hard to seperate the necessary elements from the unnecessary scrap on walls, ceiling and floor. Why not let your elements peak out by giving them exclusive space in your map?
The ceiling makes an important part in my opinion. I personally like different levels of height to seperate rooms from each other. You should definitely try that and you will notice that your room doesnt look like one big rectangle box anymore.
I'm eager to play the update
That's really useful feedback, thanks! I agree with you that it's way better to include architectural variety and adjustments to block unintended solutions rather than to place glass walls. But I had made this map from a PTI prototype. I was free for a day and that was the only time I could use hammer to totally convert it into destroyed theme. Unfortunately more unintended solutions came up after that.
Long story short, once it was done, it would've taken too much time and effort to modify the architecture of the room. So I resorted to these "quickfixes". The moon and stars thing needs a 3D skybox which I haven't learned yet, but I hope to include it in some future map (not in this one, though, as it would again require a solid day's effort which isn't possible for me right now).
About the ceiling: there actually are holes in it, but there are no stars, etc. showing through them. Basically the vegetation is hanging out from those "holes". Following your suggestion, I can add a bluish fog and at the same time increase the lighting. So the ceiling will be obscured (which is good since the ceiling holes are black and I wouldn't want the player to see them. At the same time I don't want to remove those holes, since then there would be no way for light to enter the room), and also I can increase the lighting, so the room will be better illuminated. What do you think?
The scrap on the floor may look brighter because directional lighting has been used, so scrap lying in that direction is illuminated while the walls opposite that direction will be dark. By the way, I don't understand why I should use orange light, where would I place it and how would it fit in?
The environment was beautiful, night themed...I actually felt a breeze with all the foliage moving and crickets? After some of your other maps, this puzzle was numbingly easy...thanks for that.... Gaps in the glass and over/through the fizzler walls had me looking for a while... Thanks for creating.