HQ21 used to be LV59. HQ22 will be available at XP LEVEL 56. XP requirement for HQ21 will be lowered.
Cost for HQ22 is 4.78 million wood, 4.6 million stone, 4.42 million steel. Build takes 2 days 8 hours
HQ22 defensive upgrades: sniper tower, boom cannon, rocket launcher, shock launcher, machine gun, flame thrower, cannon, and mortar.
Also provides 1 additional sniper tower and more boom mines.
For the full video go to https://m.youtube.com/watch?v=UarD5S3aX7o