Reus

There are 26 level 2 developments and you only need 9 of them for this achievement. These are the milestones awarded when you complete an era. Every development that you complete unlocks a new item/resource in the game which makes subsequent games easier. The developments marked with an * are what I consider to be the 10 easiest.

The last 3 easy ones (mining, farming & hunting) can easily be done with cunning use of an era ending save. Save before the end of the era, find a village with over 250 prosperity and replace all minerals, plants and animals with just minerals or just plants or just animals. Finish the era, reload the save and go for the other development.

*Developing Era - Finish an era with 800 prosperity
*Desert Town - Finish an era with a desert village which has 300 village prosperity
*Forest Town - Finish an era with a forest village which has 300 village prosperity
*Swamp Town - Finish an era with a swamp village which has 300 village prosperity
*Vibrant Era - Finish an era with 1000 prosperity
Legendary Warriors - Finish an era with a village which has at least 6 war markers
Great Development - Finish an era with a completed great project
*Booming Era - Finish an era with 1200 prosperity
Desert City - Finish an era with a desert village which has 500 village prosperity
Forest City - Finish an era with a forest village which has 500 village prosperity
Swamp City - Finish an era with a swamp village which has 500 village prosperity
Divided Planet - Finish an era with at least 6 villages who all have at least 150 village prosperity
*Fantastic Era - Finish an era with 1600 prosperity
*Mining Community - Finish an era with a village which has 250 village prosperity and only uses minerals
*Farming Community - Finish an era with a village which has 250 village prosperity and only uses plants
*Hunter Community - Finish an era with a village which has 250 village prosperity and only uses animals
World Economy - Finish an era with at least 3 completed great projects
Harbor Town - Finish an era with a village with 400 village prosperity, and at least 8 ocean patches within its borders
Mountain Town - Finish an era with a village with 400 village prosperity, and at least 8 mountain patches within its borders
Abundant World - Finish an era with at least 1000 food being used by villages
Rich World - Finish an era with at least 1000 wealth being used by villages
Advanced World - Finish an era with at least 1000 tech being used by villages
Survivor - Finish an era with a village which has 500 prosperity and 30 danger
Capital - Finish an era with a village which has 650 village prosperity
Great Vitality - Finish an era with a village which has at least 150 food, wealth and tech in use
Golden Era - Finish an era with 2000 prosperity