I decided to make this it's own page as there are several endings to this game- a couple of which people often miss.
Your first, most simple choice, is to just wait for Konrad to finish counting. He will then shoot you and the game will end with Walker committing suicide.
The second, most obvious, choice is to shoot yourself in the mirror.
Both these choices are logical, in a lot of ways. You are the actual bad guy in this game and you have brought forth horrible atrocities to the people of Dubai, as well as the people you commanded, and you need to be stopped. Choosing to let Konrad shoot you is more an act of cowardice even if an admittance of guilt.
The third option is to shoot Konrad in the Mirror.
Doing this is choosing to remain in delusion that it isn't really your fault- which is a fine way to look at it if that's what you see. This will, however, bring about a little bit more game play.
Don't go anywhere. After the credits (you can skip it if you want) there will be another scene.
Some soldiers will be sent in to find out what happened.
As strange as it is, you have another choice here.
You can choose to open fire on the soldiers.
This is another way to suicide yourself in an admittance that you are evil and must be stopped- although a much more devious one.
You can also choose to cooperate with the soldiers.
I consider this the most evil ending. It's basically Walker not caring that he is a mass murderer and potentially getting away with it. Or is he?
That's it. Spec Ops: the Line is one of the finest games to try and tell a serious story in a long time- if ever. It discusses many important issues in life. Enjoy discussing it with your friends, family, and whoever else is interested. As always I can be reached on Twitter (@cornbredx) with questions, but I don't read it a lot so I may be slow to respond. Donations are greatly appreciated. Thanks for reading!