Inspiration: A seamless combination of the three games you received.
Usability: At first I felt that the lack of specific area descriptions in these huge castle levels was a detriment, but I quickly realized that this is not so. I could easily run this with a (blank) map laid out on the table and the party moving square by square as they encountered NPCs, samurai, and were surprised by ninjas hiding behind corners. The layout is great. One spread for the setup, one for the monsters, and five for the levels.
Vibes: This is hilarious. A truly funny distillation of The Simpsons (via Ghostbusters and Murasame Castle) converted into TTRPG form. The art really helps sell it for me. I enjoyed reading it so much that it makes me want to run it all the more. Nice job.