Could we increase the difficulty of the karma system?
For e.g. karma is decreased if the task is 4+ days overdue. What?
I want karma to decrease when the task IS 1+ days overdue.
Any way I can achieve that?
Unfortunately, there is no way to change the way Karma is increased or decreased by user. We might consider changing this in future updates.
Please note that the higher you go, the longer it takes to gain points with Karma. This way, you won't reach enlightenment all that quickly. It does take some effort :)