The PC version of Metal Gear Solid is a direct conversion from Playstation version. Perharps a bit too direct, because graphics isn't really state-of-the-art and the game refers to PS controls. But that isn't important, the feel of the game is...
The plot: Fox-Hound, Solid Snake's former "employer", has captured a nuclear weapon and hidden it to Alaska. Their demands for not blowing a big place up with that is to get the genes of the Big Boss back. So, of course, Solid Snake and the remaining "good guys" of Fox-Hound need to sneak in and ruin this otherwise crafty plan.
PC version is fairly straightforward - sneak around, try not to be seen, kill stealthily. Oh, and talk to radio a lot. Learning curve? Hour or so.
The game also includes (on a second CD) a "VR training" mode - for shooting inanimate objects and sneaking around. It also has a worthless but odd photography section (to get sexy shots of Mei Ling... Obviously designed for those who want to use the joystick instead of joystick or something... dunno...)
(The VR Training starts with insanely funny but ultra-violent video clip... The Japanese are truly mad... =)
Vehicles of interest
Note: This has been covered more in depth in Metal Gear: Ghost Babel, its original title.
This is essentially a clone of the old NES versions of Metal Gear, with a fairly same plot (again something along the lines of "don't let them do anything with that big nuke robot thing, you know?") However, it's technically superior to the old game; You can continue near the place where you died, and it features a battery backup (no need to hassle with passwords). Also, it has a radar, something that would have been really cool in original Metal Gear.
VR training missions are, actually, for most part the same that are in the PC/PS version...
Also, it may be worth noting that the Game Boy version is in many ways better than the PS version: It can have more soldiers on screen at the same time, it has multi-player mode, and the ends of Snake's headband wave as he runs!
2001-10-28: Oh, by the way, the game doesn't have "eight days" of narrative. I just copied recorded the entire "reel A" to video tape. It's just three and half hours of narrative and stuff - not the whole chatter stuff, but significant part of it. Granted, it is three and half hours. Three and half hours...