This is obtained by defeating the second boss in the game, which is a large Death Star looking creature.
Same as before. Get your triple knives (or twin axes) and both power-ups ASAP to deal out more damage and faster with increased range or rate of fire if possible. Always have a Bubble Shield when possible and the Shield in case you accidentally die so you keep your items.
To clear a level, you only need the key to progress through the door, so do not go for extra treasure or killing more enemies if you do not need the money or other achievements.
Beholders and Watchers take a few hits to kill and watch out for hidden spikes in the floor.
*Increased Range or Rate of Fire are helpful options
First Pattern - The Boss comes in on the right side of the screen. It shoots out orbs that you can double jump over while throwing weapons at it for damage.
Second Pattern - The Boss will rise up the side of the screen to the top and move acorss the board, dropping more damaging orbs. Simply avoid them and wait for it to come down the side of the screen again. Then it will repeat the First Pattern.
*Please let me know if there is anything I missed and I will add it to the guide. Thanks.