Currently, I'm working on finishing the player assaults (better animations, add rewards/penalties, notifications, maybe some leaderboard just for assaults) and when that's done, I'll start working on player land upgrades and "Unlockables" to reward the player for character progression and leveling up (skillpoints alone are kinda meh...)

First are coming land upgrades, as that feature is long over due (I always forget about it). They will work pretty similar to building upgrades, but instead of production rate they'll increase in building capacity - ie. upgrade your land to get more slots for buildings.

Next in line are unlockables. I already have a table prepared in the database for it and couple of additional resource buildings (ecstasy presser, coca plantations and poppy fields) that the player can unlock after reaching a certain level. Another type of unlockable are going to be character upgrades, like increased max energy, larger inventory for money, etc.