Luckily they have included a more PC like save system where you just hit the ESC key and you can save that way. You also have a map that is displayed in the upper right hand corner of the screen. This will show your position on the screen and also where the enemies are. Of course it would be too easy if you could always see the enemies, so when in areas of high harmonic resistance, you can't use the map. Fortunately those aren't too frequent.
Weapons are abundantly available and can really do some damage to the enemies.
The main ingredient in MGS is stealth. Yes you can kill everyone on the screen, but you'd be better off using stealth and trying to evade enemies. Once you start to engage an enemy an alarm will go off and then more guards will show up, which almost certainly will spell your doom. Bosses are also readily available. You will encounter the bosses and then watch a nice movie explaining the story some more.