spoiler
Xen just ended up too long, imo. They should have released it as a free DLC and stayed more true to the source.
I really felt like the pacing suffered too much as a consequence. Everything up until then gives you the impression that you are heading towards the grand finale and Black Mesa is suddenly like: "Solve some more puzzles for the next 2-3 hours".
I liked it but that really threw me off.
All my life I thought that she would love me, if I achieved certain test scores or finished a certain degree.
Then there was high school graduation night. I had worked really hard to get there and I will never forget how she made that annoyed face to let me know that she wanted to leave early. It was like a punch in the gut because it became clear to me at that point that there was nothing I could do to make her love me.
She wasn't capable of giving love. That's really fucking sad and I am still grappling with it, but it gets easier.