Every 5 or 6 levels I get blocked from winning until I play 25-30 games, then they allow me to win and go to the next level. This is very tiresome. I am not going to buy boosters. Sigh. Time to retire from what used to be a fun game.
Some level can be challenging but with some patience and Clear strategy levels can beaten . Keep trying . try play events or Challenges on the game to earn booster ,