You cant use the Cross Bow in this game for some odd reason
ive completed every single mission in this game,yet it doesnt unlock the cross bow in the game.
just a quick tip for all the gamers of AC
when you want to complete missions in the game?
press the "select" button it will show you the map of the city.
Always go for "VIEW POINTS" in the city
WHat is a "VIEW POINT"? its a place where you go to scan/view certain parts of the city by pressing the "triagle" button,by this ud be able to find more missions when u look in your map by pressing the "SELECT" button and it also unlock some parts of the city where you havent been yet,go to that part of the city and look for another view point for more missons
such as "save the citizen"assasin mission"
another thing
when you arrive in a city, if you look at the map it only shows you certain missions,keep in mind that its your resposibility to find view points for more missions in the game.