In the Days of Olde, Portal 2 did not have the Perpetual Testing Initiative, which means that making Portal 2 maps required one to go into Hammer, get things set up for Portal 2, and generally scour the “Thinking With Portals” forum for information.
While playing Portal 2, the level designer in me decided “time for me to make some puzzle-y maps!” And from there btmap1_rc was created. I decided my first released Portal 2 map before the workshop would be a co-op map because I have little to no self control when it comes to aiming high.
btmap1_rc was iterated a few times and tested entirely on my own using the Portal 2 splitscreen feature. It was also the first time I used “instances” in Hammer. Overall, the map wasn’t difficult to make or design, which is why I would go on to make a number of other Portal 2 maps. This is still the only co-op Portal 2 map that I’ve created and it was also the first; so it has a sweet spot in my brain and heart.
After the Perpetual Testing Initiative, I recreated the map as “Going up together?” I still have the original version of the map, but the Workshop version is much more accessible.
Let me know if you give the map a try! (Link to Steam Workshop below)
Scooter on Youtube (Approved method of making it to the top level)
coopcrowd on Youtube (Slightly cheeky way of completing the map; they rated the map 8/10)
Djinndrache on Youtube (Also a valid solution)