Castle Ruins is the final area in Jacksmith. It is the area where the player will face Dudley. Upon defeating Dudley, the game is "officially finished", but the player can continue after.
New Items Acquired
There are no new items acquired in the Castle Ruins as the last few items were acquired in Wormwood Hollow.
This is the only enemy in Castle Ruins:
Why the few enemies?
The reason why there are very few enemies is because the Castle Ruins actually have an extremely short trail in the storyline. After defeating Dudley, the player will experience all enemies he/she experienced before plus new enemies.