In Wack-A-Doo you experience two different ages, Stone age and Copper age. While in Stone age you use simple tools to gain ressources and build weapons, in Copper age there are more progressive tools and weapons and your military organisation is improved.
The progress from Stone age to Copper age is related to the type of settlement. Home settlement and the optionable camp can progress to Copper age by building a Copper smelter or, if a camp exists, by expansion of the Gathering place. The fortress, originally built by the Neanderthals and conquered by the Stone age people, cannot be improved with the more progressive tools and weapons of the Copper age. Fortresses do not change from their Stone age standard.
Overviews to single buildings and units you find here: