Cheats
At the main menu, Press R + click Left Analog-stick, press R + click Right Analog-stick, press R + click Left Analog-stick, press R + click Right Analog-stick, press R + White, R + Black, R + White, R + Black.
Select "Start Game" and the reward menu will be unlocked. The items are: "No Rewards", "Sword Time", "Unlimited Mana", "Continuous Fire Sword", "Pencil Test Characters", "Smooth and Shaded Characters". 

The Impossible Room:
This level is not really that difficult. Remember -- everything is a mirror reflection 
of the rooms that seem upside down while you are looking up. Get familiar with 
the behavior of the room and knock it out. However, the difficult part is figuring 
the locations of the other rooms to get out of this room. The first two are easy 
because you stumble across them. When you get the Dragon's Eye (so you can 
see hidden doors), look for an eyeball on the wall. When you see it, use your 
Dragon's Eye to find the opening. There are only two hidden rooms in the 
Impossible Room. Look carefully -- one room has bonus items you need. The 
second room takes you to the Lizard King. When you get the Dragon's Skin (armor 
against fire), fall down the hole that has fire billowing up on the bottom floor. This 
will end the Impossible Room and will take you deeper into the castle (Lava Level). 

The Dragon's Lair:
When the dragon tries to light you on fire with his mouth, run close and opposite to 
where the it opens its mouth. Once the dragon has completed with its fiery salvo, 
run out of his claws reach and face him. The dragon will then directly shoot out the 
flame that you have to catch with your magical sword (press Guard). Press Attack 
to release the fire from the sword to cause the dragon pain. Once the dragon is 
vulnerable, slash it with your sword once or twice. Run out of its way when it 
recuperates. The process will start again about five times. During the second bout, 
he will fire two salvos. You can then catch the fire with your sword. During the 
third bout he will fire three salvos. You can then catch the fire with your sword and 
so on.

Pinball level:
On the Pinball level where you are avoiding the balls going back and forth, jump if 
the side-to-side pinball is approaching you. This way, Dirk will not slow down and 
you can avoid getting hit by the big black ball following you.