I'm new to the forum, so if this post is in the wrong location please correct me.
I'm looking for ways to make the game more challenging. Now, one idea I had was to add a building whose maintenance costs increase over time. The player would construct the building right in the beginning of the game. From there one, his economic progress has to outpace the increasing maintenance costs in order to maintain the budget positiv.
Does anyone know if and how it is possible to make maintenance costs time-dependent?
Any advice is appreciated.