lol thats a good way to look at it! I personally just wanted to kill, kill, and kill lol Yea you can do that. I may do that to get some achievements I missed out on.
EDIT: Im not gonna spoil the ending so I will not say much but after someone beats it I want to know their take on this. There is an achievement for killing no one at all except for the key targets but there is also one for not killing anyone at all. I don't know how this is possible?......