This is a tough thing to review. I have mixed feelings about level design - Sometimes you are told about a "door" which turns out to be a metal plate in the wall. Sometimes you are told to do damage to some crappy reactor - It turns out you're supposed to dump crates inside of it. Some puzzles were tough.
Certain fights seem badly setup - enemies in a bunch as if they just spawned and didn't even walk apart. The chase scene were you run away from soldiers without weapons. That was very fun, but you are supposed to wait for the next area to open, while most people would run away and not wait for the door assuming it was closed.
There's also the thing with breakable scene elementns. No, a sparking piece of metal in a huge collapsing cluster♥♥♥♥ of identical surroundings is not enough to attract my attention.
Despite of it's many shortcomings I suppose I sort of, enjoyed this mod? I felt more happy at the end then I did at the end of HL2, and that says something. The level design really wasn't that bad, since I never consulted a walkthrough. I did on multiple occasions during my HL playthrough and that game's level design is considered to be amazing. It's only two hours long but trust me - it feels a lot longer than that.
So yeah, check this out! Definitely worth your time. I certainly wouldn't buy it if it was paid, but it's free!