Well I first found the introduction of being woken up from a sort of suspension chamber, then encountering Wheatly the personality sphere. At first, I thought he was one of those pressured scientific sort who was at their last resort, judging from how he tried to coerce me to speak, then attempt to say apple. My reply was jumping to both requests.
I think there's either brain damage, or Chell is mute. I'm figuring mute since she understands how to stay alive pretty nicely.
The portal gun is removed from it's normal case, and instead is under a lab that is FAR FAR FAR FAR FAR below the original. Luckily, there's a shortcut. It's a very deep pit. The portal gun is actually held in a Rat Man section, with beautiful murals. One of them was even Chell.
So together we try to escape the labs. We accidentally wake up GLaDOS. She crushes Wheatly and tosses him away before dragging me off to the closest testing area. As I continue to complete tests and puzzles, she tries clearing up the areas before I reach them. The entire time we're 'testing' she berates me and calls me a monster. At one point she even says 'I was doing research on how effective sharks that can shoot guns would be, you know, for a suitable way to kill you. Do you know what creature would kill someone who was helping them? Did you say 'sharks?' Well you're wrong, only YOU would kill someone trying to help you.'
That got me pissed, so I kept blazing through the tests in any fashion that is not blatantly obvious. Wait, what was that? *loads last save and looks at what i didn't notice before* ... Was that Wheatly? He's still alive?
So I get to the spot where the projection plates are, and I jump up to see Wheatly! He starts talking but I fall back down. GLaDOS resets the calibration for the pad and launches me up again, where Wheatly seems to have not even noticed that I was gone... bastard was still talking. GLaDOS lowers the ceiling and I can't get to Wheatly again, so I continue testing hoping that he stopped talking long enough to notice that I am definitely not in earshot of him.
A test later, he pops up speaking in a southern accent declaring it as 'a way that glados cannot hear him' to which she replies with 'I can hear you, moron.' Then it's a prison break.
Now, there's a part during the escape where GLaDOS says that Wheatly's plan of escape is pretty much stupid, compared to her option which is 'complete this final test' but I took the option of an idiot who knows how to stay alive instead of pressing a button in a room that i couldn't escape from.
So we ran, switched out good turrets for bad ones, destroyed the neurotoxin container, and then took on GLaDOS. Now, at the container's area, there's a sign that says 'in case of implosion, look into implosion.' so when the container imploded, i stared at it with furious enthusiasm... also hoped that it wouldn't kill me for some reason. Then we fought GLaDOS which was actually not a fight but me becoming a stalemate resolve ambassador or something akin to that title. I pressed a button, and GLaDOS was defeated! Wheatly put me in an elevator and started to say goodbye, until the elevator stopped... and he brought me back down.
... FUCK YOU WHEATLY I JUST WANTED TO LEAVE DAMMIT.
So while I was mentally cursing him out with every derogatory word and phrase I could think of, the new Wheatly dismantled GLaDOS and stuck her into a potato (which earlier in maybe the first twenty minutes of the game the announcer says that all devices can work proficiently on 1.7 volts, which is able to be supplied via a potato battery) and then tried killing GLaDOS by crushing her into the elevator... with me still inside.
We both fall down a bottomless pit for a while, and GLaDOS requests a few things here and there.
We land. A bird picks up the GLaDOS potato and I just try to find a way out of there.
I come across the old testing areas, as well as the GLaDOS potato.
I found it endlessly amusing to mess with the orange, blue, and white paints to solve puzzles, except for one that was incredibly simple if it wasn't for the fact that the white paint was there... ironically.
Then we continue on through the tests, hearing Cave Johnson's recorded messages all the way. However, when he asks for a stack of documents from a Caroline, GLaDOS says 'Yes Mister Johnson' and then freaks the hell out because she has no idea why she said that. It later turns out to be that Caroline is IN FACT GLaDOS's original personality. Seriously.
Also, if life gives you lemons, SCREW THE LEMONS AND TAKE LIFE BY THE THROAT AND STRANGLE IT INTO SUBMISSION. Then burn down someone's house... that's some advice from Cave Johnson right there. Also ground up moon rocks are pure poison. Keep that in mind.
So we drop across some of Wheatly's experiments... which are turret boxes, or box turrets... they're boxes with legs. They're cute as hell... boxes... with legs. Though up close they freak me out.
I helped the little 'buggers' out by putting one on the button. Wheatly shows up on a tv screen and has us do more testing.
As we test, I learn why GLaDOS was so adamant on the testing, because there's a sort of itch when no testing goes on. When you try to help the test subject, you get an electric shock.
As Wheatly makes more testing grounds, he wrecks up the place and there's even a spot where he's talking about finding an exit in a room... and I see P-Body in the distance, looking back and forth before booking it out of the area.
Well Wheatly quickly turns into a british male version of GLaDOS and then he kills us... or at least tries to. I'm willing to bet that he didn't count on there being a white paint drip in viewing distance, let alone me being fast enough to drop portals. So I try escaping. Oh, and GLaDOS is impaled on the portal gun. Did I mention that? Oh, okay. Well that's what happened.
We try meeting up with Wheatly to dismantle him, or at least get GLaDOS back into position. There's a part where Wheatly talks about great artists or minds versus each other. 'Aristotle vs SMASHY SPIKE PLATE!' is heard while he crushes a catwalk that I was supposed to walk on. Unfortunately, one of the legged boxes was there instead... though he is still alive. What a trooper.
So I continued on, and came up to Wheatly after GLaDOS points out some corrupted core pile on the way. So the plan is to stun Wheatly, and attach cores onto him... so he couldn't do anything effectively. I liked the plan, sort of like... a reverse of how you kill GLaDOS before.
Water bottle refill break.
Checking time. Huh... nearly 6:30 in the morning.
So we meet up with wheatly and he lists off the things that GLaDOS did wrong when she tried killing me. First, no turrets. Second, he actually adjusts the shielding panels to block attacks. Third, the neurotoxin is started right away. RIGHT AWAY DAMMIT. Oh, and the labs have around six minutes to explode.
Portal placement, some bomb tossing on his part, and then bouncing off of blue paint to dunk personality cores into ports street ball style, and wheatly requires to be changed. So a stalemate occurs, and I have to press the button (again). Well the bastard put a fence up in the way, but then again I noticed that there's a plate above the button that could hold a portal. I shoot, I jump into a different portal from earlier, and drop down, smack the X button as fast as i can, and HOLYFUCKINGSHIT THAT JACKASS BOOBYTRAPPED THE BUTTON! Then he gloats about boobytrapping the button. Bastard, I'll show him.
I pick up the portal gun and with my last ounce of strength I shoot a portal to the moon...
wait, there was a blue glint in the distance.
The area suddenly tries to evacuate through the orange portal below Wheatly and pulls his sphere and connection out the blue portal. I fly through and grab ahold of his handles because i couldn't grab onto anything else in the first place...
Then GLaDOS saves the day! She smacks Wheatly away and pulls me back in.
I wake up, and there's a couple of robots there. :? (Atlas and P-Body)
Then... I get the moral of the story from GLaDOS' point of view.
Then GLaDOS deletes Caroline from her mind, and starts to lift me up on the elevator.
Then on the way out... I get this: http://forum.ianti-virus.com/viewtopic.php?f=145&t=17700
Then when I step out of the shack, and take in the beautiful view of being on the surface for the second time in my life... I hear a door slam, and turn back to see that it's closed. It suddenly opens again and spits out an incredibly burned companion cube...
then the credits roll.