To anyone who is doing hard at the Piano Chase: It IS very hard, But passable. Jump OVER the ramps (Jump when you get close to them). But this level could be easier.
I have an advice:
Do not upgrade the Barracks, And upgrade the Archery onces. Unlock the Dwarves and the Hobbits, And use Wizards instead.
I've almost passed level 6, The enemy castle had only 114 HP left. I did it only with Wizards and Hobbits. Hobbits are VERY important. They are fast and can delay the enemy, Just keep send them. They are also very cheap.