I just finished playing the PS4 remastered version. Wow! From an artistic perspective, I found the game to be superb in all respects: storytelling (aside from the fact that I don't think you can vaccinate for fungi), cinematics, dialogue, voice acting, animation, set pieces, music, sound, you name it. It even was emotionally engrossing.
From a gameplay perspective, I found it engaging and challenging (even on Normal difficulty), though I became impatient with the stealth eventually. On some of the longer parts, I would get frustrated when I would painstakingly use stealth to avoid or kill enemies for twenty minutes only to end up dying and having to start the whole thing over again. I found myself just trying to run through the stealth parts in later levels or, if that didn't work, use firearms to take out the humans.
The ending was powerful. I wasn't sure what to expect. I found myself wanting to have a say in the outcome and am still not sure I'm totally happy with the way the game ended. The ending itself was well done; I just wish there was a way to chose.
It was especially tough being forced to kill the surgeon and assistants. I can't imagine there are too many of those around. I guess the point of the ending is that Joel is a flawed character and he can't bear the thought of losing another young girl that he was close to, and he's content just to live out a small life in Jackson City even if it means that no cure is found.