Strategy

Surviving the early castle is rather easy, but the more rooms are added to it, the more and better equipment is needed. One should keep in mind, that the inventory has limited space and throwing away useless items can be helpful. During the travels through the castle, it's easy to collect enough coins, especially when one runs into a boss (like Eye or Eel etc.). Monsters most often drop coins.

Places to go
In case you missed it, the Witch of Sausan will tell you again: VISIT the castle's catacombs!
 * But use a Invincibility Potion!

Useful items, general

 * Keys - You will need them - often - and many!
 * Health Potion - Monsters might harm you, but there are also spikes and traps! (oh, and lava!)
 * Invincibility Potion - in case you meet a boss this is pivotal!
 * Weapon of your choice!

Useful items, when the castle is getting larger

 * Compass - can direct in the right way
 * Crystal Ball - shows how many rooms there are between you and the princess