Zombie Hunter/Level 6

If you do not have a good physical weapon, then it is highly suggested to get an extra Key 6, which, surprisingly, hits harder than most of your other weapons.

First quarter
Shop item: Medicine 2, Medicine 4, Necklace 6.

Second quarter
Shop item: Medicine 1, Medicine 3, Hourglass 7.
 * Found at the middle pot between #10 and #11.

Third quarter
Shop item: Medicine 2, Medicine 6, Magic Book 6.
 * Found at #23.

Fourth quarter
Shop item: Medicine 2, Medicine 4, Medicine 6. Also note that, Dolgo always drops Life Seeker. Picking it up will earn the ending.
 * Found after #25.