During Portal 2 you will get plenty of trophy/achievements throughout the game just by beating it. That said in Portal 2 they have plenty of missable trophy/achievements. The ones we will be looking at today are both in chapter 2 test chamber 6. The trophy/achievements are called Final transmission and Pturretdactyl. Lets get on with it.
In Portal 2 every time you get to a new chapter it shows it on the screen so make sure you are in Chapter 2.I would advise a save before you start this just in case you mess up
Test chamber 6 is the room with a ton of water and like 5 jump pads. Before you use the jump pad make sure to place your portals in the right spot.
Once you enter the room head left to the end then look right until you see two white walls on an angle. Shot a portal on each of them then use the jump pad.
It will launch you to a red button which you will then push. Glados will launch some trash at you and it will go through your portals. Among the garbage will be a radio. Pick it up and then head back to the start of the chamber.
Okay this next part is a bit tricky. Once at the start put your portal on the first wall you will hit with the jump pad. Then look up and the the left a tad bit and zoom in and you should see a white wall. Put your second portal there and grab the radio and take the jump pad. If you did it right you will end up in a different room and get the trophy/achievement Final transmission.
Alright for the trophy/achievement Pturretdactyl you will need the turret from the trash Glados launches at you. The turret won’t make it all the way to you so make a portal and head to it. You can see the laser sight from it and if not it will be at the place you put your first two portals. Grab it and head back to the start and put it on the jump pad. After a few seconds you will get the Trophy/achievement Pturretdactyl.
So there you go the trophy/achievements for Portal 2 Pturretdactyl and Final Transmission. I’ll add some more as I go through the game if I think they are missable. Enjoy the game!