the key t the final few boards i figured out is spam fire bcause while your bombs are hitting the buildings and they are still "wiggling" so to speak you can have more bombs incoming which does even more damage. ifound by doing this at a 80 degree angle on the final 2 boars helped me to finish these boards easily.
 "Crush the Castle"){kind=icon}
 "Indestruct2Tank"){kind=icon}