I've observed that when you kill the first group of enemies you meet in Chapter 5, with the default silenced pistol and without any enemy being able to fire a shot, enemies won't be alerted to your location and Max Payne will comment on the stealth kill. (I'm not sure if not doing a stealth kill will change how this part plays out, though [like enemies being alerted and immediately attacking at that part if a non-silenced weapon was fired]).
However, it seems that this doesn't seem to be the case with the next group and the rest of the enemies you will encounter in that chapter. It doesn't seem to matter if it is a stealth kill with a silenced weapon or if you use non-silenced weapons – all the enemies in the level will seem to be alerted to your presence if you engage in a gunfight with any enemy. This leads me to believe that the 'silencer' of a weapon does not really matter that much in most parts of the game.
Hence, my question: Which parts of the game's Story mode, will successfully doing a 'stealth kill' with a silenced weapon affect gameplay? (i.e. Max Payne commenting on the stealth kill, enemies not being alerted to your location or other gameplay changes)
Best Answer
The silenced weapons you come across in the single-player campaign will have a very limited one-time use. In the levels that you get them, you're only able to use it (with any effect) for the very first fight you get into. After that, every enemy you encounter will be forced on you.
There's only two instances of when you get a silencer, at the Tiente Docks in Chapter 5 and the Crachá Preto Hotel in Chapter 12.
In chapter 5, you start the mission with the silencer and will come across two guys loading a truck. If you are able to successfully kill them both quickly without them being aware of you, that will be the end of them and you can move on. If they see you, more guys will be alerted and will attack you.
But even if you were able to kill the first two quickly, there's no hope for you to be able to stay stealthy for long. In the very next section, you will be forced into a firefight. You will be hiding behind a window (in a very awkward position) with two guards being suspicious of your location. There's no way to get away from that position without them seeing you. Going into bullet-time in the hopes of shooting them first will be fruitless as you will have to break the window and that will alert everyone. There's no hope of staying stealthy, every wave will be alerted of your presence.
In chapter 12, you will fashion a silencer with a bottle taped over the muzzle. Again, after exiting an elevator, you will come across two guys. Again, you will have an opportunity to take them out quietly but it won't matter. There's two more guys in the next room that will rush in no matter what. You can kill them quickly but it's not going to matter, nobody else is around.
After dealing with those four guys, you'll see a guy standing in a hole in the wall. Kill him or not, it won't matter. The group of guys in the next section will be alerted.
In the end, the silencer is just a waste. You only really have one opportunity to use it where it affects the fights you are able to avoid. Otherwise, every fight you do get in you are forced into. So don't hold your breath thinking you can play through the game like a ghost, it's just not going to happen.