Detriment for not completing a task

In the app there is reward for completing tasks, however for someone looking to progress in the app and in real life, there is no drawback to not fulfilling these tasks. You either move forward or not at all, but you never move backwards. It would be nice if there was a feature to enable for more strict users where not fulfilling a task meant LOSING something, whether it be bananas, structures, etc. This would provide more incentive for not missing days, and realizing not doing a task can sometimes have a negative impact.