Short, sweet, and leaves a good taste in your mouth after you're finished, but lacking in substance. As someone who played the second game first (child me didn't understand what sequels were), this game has always been overshadowed by it, but coming back to it, I think there definitely is reason why it garnered the respect it did. The slow peeling back of the faceless, clinical "tests" as the game reaches a climax is very well done, and the atmosphere is some of the strongest in any Valve game; as my friend put it, it feels like you're the last living thing on the planet at some parts. There's certainly no real dip in quality, the puzzles are very consistent throughout, but I really feel like a mixture of time and the sequel have not been too kind to this game. If it were still 2007, this would be an easy 5/5 for me. For now, it's a solid 4/5 with a 5/5 in the atmosphere department.