Estranged: Act I is a horror FPS that starts out strong and then peters out into mediocrity, a testament to its shortness.
For starters, the game looks decent. There's a mix of Half-Life 2 assets and custom assets, but it's consistent enough to work well. The custom graphical effects and use of dynamic lighting are also very well-done, even if the depth of field is a little strong. The levels are well-constructed from a visual standpoint, the music is fitting, and the game doesn't rely on jumpscares to pull the fear out of you.
That said, the game's mechanics are so recognizable that the horror element won't last longer than, say, 45 minutes. The zombies you fight never really felt challenging. The scare was more "me not knowing what they're capable of," and it gets easy to see what they're capable of. Also, the game sometimes puts them in cheap places. I feel like enemies this simple could be much scarier if used in different ways.
In addition, you also fight a few non-zombie combatants. Their AI is good, but the main danger comes from the fact that they can kill you in a few shots. Unlike Half-Life 2, you have to be careful and take cover constantly. It's a decent amount of fun, but there are really only two spots where the game plays with this concept. There's also a mandatory "crane" section, because that was *totally* fun in Half-Life 2.
The crane bit brings me to one of my biggest complaints about Estranged: Act I: the level design I said before that the levels were well-constructed from a visual standpoint, but from a game standpoint, they're bad. The game uses the Valve trick of light and darkness to tell you where to go or what to do, but none of it makes sense in the game's world. Just random spotlights that have no reason to be there. The levels are straightforward and most of the time are just corridors with nothing happening. No chance for implied stories or combat or navigation. The levels aren't compact, practical, or even useful, in some cases. It feels so disjointed. I felt like there was never a reason for most of this environment to exist, and it killed the immersion for me. I haven't seen level design this impractical since the original Half-Life.
Then there's the issue of length. The game is VERY short. It's free, yes, but that's no excuse for breaking it up into tiny segments like this. There's no story development, none of the characters are even remotely interesting, the player character is even more of a blank slate than types like Gordon Freeman and Link, and the pacing is nonexistent. I don't care if this is an episodic game, you still have to take me somewhere that isn't another shooting gallery. Telltale and Valve have both proven that it's possible to make episodic games with pacing just as good as their full-length big brothers. When the game ends, it just kind of...ends. There's no climax or falling action. It's just "Welp, you're done! See you later!"
I wouldn't be so upset with this if it weren't for the fact that this game shows potential. It looks and controls great, and I was genuinely scared in the beginning as I crept forward, anxiouslyt waiting for something to pop out that never came. It's just that the game lets its guard down so quickly and devolves into the same routine. It's too recognizable, the level design is unrealistic, and it's over before you know it. Hopefully Act II can fix these mistakes. I would be surprised if it did.