Soul Limit is automatically consumed when a magical girl's body gets injured to heal it, even if that would cause her Soul Limit to run out and die instantly. Players would rather forego the healing if Soul Limit is that low, especially if the character is close to defeating a witch...but Kyubey wouldn't.
Even though the girls focus should solely be on working together, you'll find competition for levels and highest score creep into playing with even your best buddies...just like the girls in the show competing for Grief Seeds when working together would grant all of them a higher net-gain of Seeds.
Which Homura you select determines which timeline you are playing in!
Madoka's special attack is ridiculously powerful against Walpurgisnacht. It is this same attack which kills Walpurgisnacht in the anime.
Mami's special attack. It was the same attack she used in the anime before she died. In the game it leaves her with barely any health.
Kirsten is a pushover Monster of the Week in Canon, but has That One Level in the game. Sayaka is the one to take her out in Canon, and is the ideal choice for the bitchy level in gameplay. Kirsten lost that easily because she faced the worst possible match-up.