I am only a few chapters in and while worldbuilding, level design and soundtrack are pretty good, direction is sorta mixed bag. HL2's default AI sucks smelly dicks, so Valve had to compensate by introducing setpieces and interesting set-ups for combat, while this game doesn't quite pull it off. Battles are nothing special, in short. Also, a bit too often levels are claustrophobic and/or dark. So rarely do you see sky in this game that it becomes a reward in itself. While one could argue that it was the intention, the string of tunnels, ruined apartments, corridors, etc becomes boring after a while.
Still, it is a quality effort and level design together with worldbuilding carry the game. If you're hungry for some HL (like I was), it's a must play. Otherwise, you have my soft recommendation.