Quick answer
Use Stone Age and Iron Age as verified live stage names inside the broader Prehistoric Times era, then learn path coverage, placement zones and upgrade timing from your current run. Keep enough flexibility to react instead of copying an unsupported fixed build.
Chrono Warfare TD is still described as unfinished and in development. This guide therefore treats the live client as the final authority for menus, stage availability and changing balance. It does not infer wave counts, tower costs, damage, enemy health, drop rates or rewards from incomplete footage.