How about more Keycard Battles to be able to choose from? I mean by this, how about being able to get those tokens that allow you to upgrade your character's abilities/special features.
Also why do they all have to use 50 energy? How about 25 Energy for half the benefit/reward so that I can better choose between the different options?
Why do I have to waste time in replaying challenge missions? Some of them have 5 opportunities and if that is not bad enough, you have to wait in between before you can do the same one again. This is lame. Why not allow me to use my sim tickets, when it is obvious that I can beat it each and every time? Or how about not having a timer in between so I do not have to sit and wait?
Otherwise the game is decent. There are numerous balancing flaws as is evident in the characters one sees each time they go to fight another player. There should be other strategies that are competitive and true alternatives to just one dominate strategy.