User made single player mod.
Took me a little over an hour to complete. It was like a mini version of HL2 with most of the major enemies/gimmicks along for the ride.
You are a prisoner in the prison that Gordon and Alex storm in HL2. You goal is to get out of the prison during the chaos.
Note: I never saw Gordon, Alex, the G-Man, or any other familiar face.
Right out of the gate, the game feels and looks like Half-Life. In fact, nothing is different in terms of enemies, weapons, allies, and the overall look of the game. This is just a HL side story ala Blue Shift or...what's the one where you played a special forces guy?
Anyway, one of the most jarring things about the gameplay is not having the grav gun. Funny how you get used to some things. No matter as there was really only two moments where you needed to move some items to proceed forward.
The part where you really miss the grav gun is to deal with turrets. Instead you need to rely on grenades, allies, or getting in close and knocking them down.
The pacing here is solid and shows some really good design. There are a few slow moments, but they do a nice job of setting up suspense for the high action moments. Of those, only a few were annoying in that I had to replay them after seeing what the designer was attempting. (And only one real "sneaky" move by the designer that could be considered cheap. Hint: It involves an easy kill for an enemy that wasn't there before.)
Still, everything proceeds very smoothly and logically. If you sit back and reflect, you'll see how things were on a rail, but during the play, you don't notice it as things are moving too fast.
Note: One smart thing here is that the mod is completely stand alone. Any future "official" storyline would be highly unlikely to rewrite it's history. In fact, it could be argued that the main character could be used by Valve in the HL universe.
An extremely well done mod that's worth the time to download and play.
7 out of 10. (A mod score, so don't try to compare it to a full game's score.)