Can we add some tasks with different ranks of difficulties in the game. For example:
1) You should kill more than 3 people in a round and survive, when you will collect 10 rounds of this task you gain money or XP.
2) Master kill - kill 3 people in a raw - and you will get something unique
3) Hit more than 5 enemies
And so on and so on.
As a prize of comleting tasks, you will get money and XP, also some unique item can be added as prizes
So we can think up a lot of interesting tasks to complete. I think it wil give more fun to the game.