Good puzzles and new mechanics (not as mind blowing as in Reloaded).
The plot is mediocre, kinda get tired of such type of jokes. Also few things are questionable considering the lore. There's a lot of segments between puzzles where you just walk and explore the same locations like you did in og Portal 2 or another mods (enjoyed "surface" tho) and walking speed is painfully slow. But if you hug walls it will be twice better.
Ending was rushed and ended on half-cliffhanger.
Voice acting is another story, sometimes I wished there was a mute button. Core that doesn't sound like core is cringe.