Upgrade map
Like heres example
Level 1:add 2 square around perimeter of how far u can see
Level 2: add 3
Level 3: u can select a oasis type and level and it will find the closest type to you
Level 4:u add 1
Level 5:u add 3
Level 6:u can select one of three mode one u can see all oasis and u cant see ppl u can only see oasis and fort amd another onee u can only see other ppl city and u can select what level u want to see and another u can only see thing that belong to other ppl
Level 7:add 3
Level 8:add 4
Level 9:you can type a level in and it will find person that level near you
Level 10:add 5 and you can enter someones city and u can see on map where all their sub are all their oasis and all their fort
This is only a example idk what it would be but if it was this good the higher level should cost coin