Here's a TLDR for the impatient readers:
It's great, if you love Ps2 style horror games, go get this one, you'll feel at home again.

This is exactly the game it was intended to be, a love letter to early/mid 2000's Ps2 horror games but with a modern touch in some areas.

Playtime:
I finished my first run on the "intended" difficulty in about 6 hours. But I'm also someone who explores all the areas to make sure I don't miss anything. So depending on your play style in might be 4 to 7 hours if you want to find everything and explore all corners.

Presentation:
The graphics style is very much Ps2 inspired, but with a crispy edge to things. It does have a very specific moody color pallet that evokes a overall somber feeling, so don't expect a very colorful game. It takes mostly place in a long abandoned UK landscape and town during rainy weather nighttime with a few hints of color and light of whatever home appliances, lights and other powered elements are still functional. And because of that light and color stands out a lot more in the eerie darkness.

The inventory and map interface are very well done and ties into the Cyberpunk style of digital imagery and scanning technology you'd expect in a 80's sci fi movie.
The game also does a fantastic job with weather effects and rainy moody ambiance. The way lightning lights up certain sights of horror in the right moments makes it feel very cinematic in a more classic style of horror.

There's also a large amount of environmental storytelling and the world building is very well done. Not all rooms you visit will be essential to your progress, but are extra spots to help paint a bigger picture and you can choose to exploring everything or focus on your main objective.

Gameplay:
I was using the standard controls (you can also choose classic tank controls) and it played very smoothly, no problems there. Melee, aiming and shooting is very straight forward with an auto target system so you can focus on timing and movement. There's a familiar set of horror weapons but also some special ones to make things interesting.
Puzzles are a nice mix of information gathering, switch flipping, item combining and finding the environmental context after reading a riddle. It fits the Silent Hill-style formula very well in that regard.

Storytelling:
There's some genuinely good voice acting and writing in this game. It's always refreshing to see horror set in a non-American English speaking setting with different natural sounding accents from corners of the world you don't hear in a game like this very often. This gives the game it's own unique voice rather than repeating the same cliche sounding lines we've heard so many times before. It's something different and this is good. The game tackles some heavy subjects and you will encounter echoes of the past that tell some very sad desperate stories of people who are stuck in dire situations. And like with many horror stories these moments echo things people struggle with in our lives.
The main plot also did something that I hoped a modern horror game would do. I don't want to go into details and spoil anything, not even with tags, but what Nath did here made me smile since a lot of horror games follow a specific trope but this game avoids it and there's even a bit of dialog addressing it, if you understand what it's trying to say to the player. The end is also very interesting and you should keep watching at the end.

Conclusion:
All in all, it's an excellent horror game that is crafted with great care by ONE really passionate developer with a taste for intelligent horror, helped by a great cast of voice actors and artists. And I can't wait to see what new project Headware Games will make next.