Forgive me if I am going through points which were already discussed. Once I am through with this post I will read the previous discussion.
However, I have played Arcanum many more times than I want to admit, and want to give my unbiased opinion. It's a game I keep coming back to and introducing others to it.
So, I loved Arcanum! Why?
-I loved the setting. It was unique and very well done. The seriousness which the Victorian-esque setting was maintained, with both grim and playful aspects present, combined with its treatment of all of the races and their interactions, and how the graphics complemented all of this, made me want to share it with people. I liked the realism of the tile settings and the models of the bigger things(The caladon palace, the steam engine, Bellogrim's skeleton). I also loved Mazzerin's mystery.
-The sheer amount of options. There were so many dialogue trees with multiple ways to access them and a myriad of ways to complete quests. You could play your character in so many ways that I still don't know all of the options.
-The amount of twists in the main plotline(I also loved the play on the name "Nasrudin"-in fact, I liked all of the "referencing" names.)
-All of the hidden locations and things which you could only pick up or only buy.
Really, the game reeked of creativity through every item, quest, and location, and that is why I love it so much. It really created this world which I could come back to multiple times without it feeling stale. So many tiny things were included-like the newspapers in tarant! It really rounded out the world, all of those little things. And, of course, the mountains of sidequests.
The story also did not just mention random forgotten kings or queens randomly. Yes, certain authors or people in the cemetary were mentioned once, but I never thought "Why is this famous king/queen's artifact so underpowered" or "This is the best that the ancients could manage?" In fact, when we explored ancient places they were usually quite impressive. How all of the elements of the story and plot came together was very organic-it felt almost like real history.
What were its flaws?
-The combat! Real-time was horrible. Turn-based was good, execpt that your followers are so, so stupid.
-How stuck you can get. We see this with Chris's videos. Once you work out how to optimize things the game is pretty smooth sailing, but if it you make a wrong turn in character development or don't quite understand how things work, it gets very frustrating very fast.
-How many bugs there were. A subset of that was that, say, if you killed someone and ressurected them you would still botch a quest. Even if you did certain things it didn't affect characters it seemed like it should have(though there were many times I was surprised at what was affected.)
-Sometimes the game was almost too much like a puzzle game. Not to say that sidequests shouldn't have hard puzzles.
-The restrictions of the the tile set.
I hope that you find all of this useful.