Nearly everything improved over Metal Gear, you see a lot of similarities between this and metal gear solid.
Cons: May feel outdated.
After Metal Gear being an unexpected hit, Hideo Kojima was inspired to do an authentic sequel (after the non-canatical Snakes Revenge). There was a lot of effort put into this, and nearly every aspect is improved over metal gear and snakes revenge. This game takes place 5 year after the original in 1999. After the cold war, oil supply has gone down. Dr Kio Marv has a solution to this, called OILX. On his way to a conference to present OILX, he is kidnapped by an island named Zanzibar. Your mission is to save him.
Again, you take the role of Solid Snake, who has retired from foxhound and brought back in to take this mission. You can tell that Konami was trying to make Snake a better character in this game. For starters, he has much more lines. You still wont learn much about him through the game, though he is still an interesting character. After the death of Big Boss, you are instructed by Roy Cambell, the new commanding officer of FoxHound. Other support includes Holly, disguised as a journalist to infiltrate, master miller, and others. You eventually learn that dr petrovich, the creator of metal gear in previous games, has been brought back and being forced to work on a new metal gear project, and it turns out that the one you killed last time was only a prototype, and that Big Boss is alive and in charge of Zanzibar. The game has a lot more plot twists then the last game, and is more heavy on story. The gameplay has been heavily revised. The gun problems with range have been fixed, making guns much more useful. You have a lot more items in this game too. The key card problem I mentioned in the last game has been, for the most part, fixed. You now have only 3 cards (once you find them): red, blue green, and although you still have to guess which one of those to use, picking from three is better then picking from 9. You are now given a radar, showing enemies on it, which is very useful to not get ambushed, as in this game enemies can move from screent to screen, unlike in metal gear. Their all-around AI is better now. They react to sounds like gunshots and hitiing the wall, as well as footsteps on certain types of floor. If they catch you, like in metal gear solid series, they will be in alert mode, and you must evade them. Snake is also given crouch and crawl, which is useful to hide under tables, beds, etc, to evade guards. The bosses are great in this game. From a huge helicopter, a ninja, to metal gear, they are all fun and require your full arsenal of items. The graphics are tremendously improved. From characters to the enviroments, they look incredible for an msx game. Same thing for sound.
The game is quite a bit longer then metal gear, ranging for about 5 hours. However, this assumes that you know what to do. There is still backtrackign and confusion on where to go.
Along with metal gear, this game is included on subsistence, and I highly reccomend you play it, before other metal gear solids if you havent played them yet.