It will be interesting to see what Telltale games will do with this. As most of you probably know, Activision has given them license to reboot the series, and as the first game in the series to have an actual plot beyond a treasure hunt, it will likely be given an official remake. This leaves us with one question: how many fans will accuse them of ripping off the unofficial remakes?
Seriously, any game from over 20 years ago with TWO remakes that highly dedicated staff made for FREE has got have had an impact. I've never seen another game that deals with slavery, human sacrifice, piracy, and other fairly mature topics in such a manner. Even Dragon Age: Origins (which has all three of those topics!) doesn't come close, partially because those bad things are what happen to "other people." Yes, there is a pirate in Dragon Age, but she has a brief appearance and the reality of piracy is downplayed (they are just murderous thieves on water), and while there is indirect mention of human sacrifice in that game, it comes in the form of a blood-stained altar that could be anything else if it wasn't explicitly said to be human blood.
Which brings me to the Best Part of the Original; the fact that the creators were bold enough to make the character play as a slave, and to show the horrors of that practice, including arbitrary treatment of another human, and the unjust sense of entitlement the master has over the slave. It is hard to imagine a major company making a game about that topic today.
The worst part of the original was the timing system, including having to wait around for long periods, and the possibility of missing the pirate ship.