The Longest Journey is a LONG journey of our main protagonist, April Ryan. She's confused, clumsy, ♥♥♥♥♥y, and sometimes can be manipulative too (well it's the nature of the point and click genre), but you'll love her! You'll get absorbed into the witty, funny, and deep story about "Balance", it's just like reading a really good novel that you can't put down once you started reading it. The writing is just so good, it's worth mentioned again, it's so good! And the voice cast is seriously GREAT, they not just speak, they 'live' the role. Sometimes the dialogue can be so long and take a lot of time, but I enjoy every single of it (Hell I feel guilty if I skip the dialogue!). It's one of main strongest point beside the story of this game, simply amazing. If you play the game and reach the point where you meet Crow, the most narcissist bird you've ever seen, you'll know what I meant.
The art is masterpiece in concept, but when getting compared to modern games, it's still good but you can see some limitations in the execution, especially in the character department. The character's polygon still rough, sometimes the animation get glitch and weird, but hey what games in that year doesn't? If you see the art concept by their artist, you just can't imagine, how great the visual will be if its getting remade with technology that we have now. Thank God it's happening right at the moment!
The puzzle is cool, some are smart and fun, some just aren't. In some points you need to go back and forth one place to another, moreover if you miss one dialog with one character, or miss examined that one tiny point of the scenery, sometimes it can be exhausting. Some people simply just attracted to the story and get annoyed easily when get stuck, it's understandable. If you want to take the 'fast lane' I recommend the guide of UHS Hints
because it reveals the only information that you need at the time, one by one, so you will not be spoiled. I still recommend to solve the puzzle by yourself though, because of its rewarding feeling.
The game has one of the most satisfying ending, the feeling you got from finished that Bioshock game, it's there. I don't want to spoil too much, but I just want to say, whatever made you stop and not finishing this game, for god's sake just-finish-it. Even it takes a long time, just like me :) English is not my first language; I reopened the game after have better vocabulary, and it's the right decision
Well, here I am, 14 years later, finished the game, and now I can confirm when people said that this game is one of the best adventure game ever made by human, it's true.