Use scroll down and select the arrow that is pointing in the left side press it and press the assist
Extra attacks with mrs. Marvel
If your last attack for the first wave (the attack that kills the last enemy in the first wave), is mrs. Marvels first attack with kree speed, for the entire next round she will attack twice every turn. However, if you use kree strike again or recharge it negates this effect and she will go back to attacking like normal.
Play same mission again and again
If you play avengers alliance, you will have to face chapters that many missions. You can play the same mission again and again and easily earn extra money and command points.
Also whenever you earn a lot of gold, you may redeem it as command points or S.H.E.I.L.D points.