This is very true.  Once you upgrade your town to level 21, that is basically it.  If you want to upgrade further you have to pay money to at least purchase time boosts.  More realistically you would need to purchase both resources and time boosts.

After level 20 or 21, you have to decide whether to pay money and keep playing vikings war of clans or stop playing vikings and move onto another game.

       What's killing this game is less adventure, few graphics and work work work for upgrades that are costly (where's the fun in that ?!), my Nintendo has more adventure and less upgrades than this game and I have been a member here going on three years and STILL upgrading !

      Then there's the trolls, they need booted straight back to the pile they came from.