3) Strengthen the Emotional Bond between Players and Soldiers

A common criticism attributed to the recent XCOM games is that, while the appearances of your soldiers can be customized a lot, there's nothing really that can be done about their... substance. All of your soldiers act the same, talk the same. They are devoid of personality and character.

Because of this, the game can sometimes feel shallow when the soldiers you recruit, become close to, and eventually lose don't really have any depth to them. They don't have characters, really, or backstories, and it's hard for the player to bond and really care about them. 

The gameplay would really be enhanced if they worked to create a strong bond between players and their soldiers. “I don’t care if this soldier dies” should be a thing of the past.
Each soldier should have their own individual personality, voice, and dialogue, making each of them a human being that the player can truly care about.

 
Brotherhood.