This game is incredibly pretty. Probably the prettiest Source Engine game to date.

It's a fantastic little urban exploration game where you go around taking pictures, solving puzzles, and fixing the city's infrastructure. It's simplistic in nature but it pulls it off really well. The environments are beautifully crafted and they really push Source Engine to its limits. Even areas where you spend maybe 5-10 minutes are meticulously crafted and modeled after real-life architecture and civil engineering projects.

The theory and infrastructure featured in this game is EXTREMELY well-researched! I think engineers (in particular civil engineers, those that work with power plants, water treatment, chemistry, transport or logistics) would get a huge kick out of this game. It explores these kinds of environments without feeling like a "work simulator", and that is just amazing.

The game takes almost exactly 20 hours to finish for your first playthrough, but completionists beware: there is a lot to do in this game, and plenty of things to miss, too. I probably don't see myself replaying this game, but there is replay value to be had here for the completionists so do keep that in mind.