Prior to release they talked about the length
Highlight to read:and it's not nearly as long as they said it would be. I don't know why they got rid of the diversity vents. They could have built more puzzles. They clearly had more puzzles that didn't make it in. Where were the balls? I guess those weren't that great. I feel like each section where they introduced new mechanics could have been a bit longer too, it felt like they were being constantly piled on. The game is constnatly moving fast fast fast, could have slowed it down a bit, paced it more, had more of the originals cerebral puzzle. Maybe had more of GladoS's clean and perfect chambers rather than immediately breaking you out again. I kept thinking that maybe once glados returned to her throne she would want to test again since It needed more portal 1 like sections.
Every second is non stop epic which is great, everything was great, but since it's such a huge divergence from portal 1 they should have paced it a bit longer with some more portal 1 like section at the beginning and middle. The old sections were awesome, made me think of black mesa. the overgrown sections were awesome. there are so many different styles, so many different areas of the facility that are constructed in different ways with different styles. it is so much more in that regard than what i was expecting
also good job valve, for making source no longer janky(by improving the loading/no more stuttering/and the menus)