Evolution Worlds is also missing a healthy chunk of content from the first game, IIRC. Something like missing at least two of the dungeons or some such? The Sting article on HG101 spells out the differences a lot better.
Metal Gear Solid: Twin Snakes does a pretty good job of standing on its own from Metal Gear Solid. It very much is a new game, just with the MGS levels and storyline in there. The gameplay is pretty different, the AI is totally different, the cinemas and voice acting are all new, etc. Personally, I hated it (awful control and bipolar AI).
SoAF was released on PC as well, if that means anything.