I'm not completely sure. I only have limited information, after all. But the instructions we were given mentioned we could be rewarded with "wishes" for completing the tasks given to us. Our captors have already confirmed that people can be rewarded for committing homicide as well.

Why offer rewards on two fronts? Any sane person actually seeking a wish would choose to earn it through task completion, and not murder.

[a pause, before he adds]

Presuming all of them are as harmless as my own.