https://docs.google.com/spreadsheets/d/1mQ4FrlgifQGJmwal5MD5a5NUJr4x3d3T-T5JE8YDTv4/edit#gid=0 This googledoc is very old and outdated (last edit from 2014) however it still has videos of every boss fight, along with strategies and comparisons that are still useful today. You can even view how the leaderboard standings were right before AGDQ2015.

TASVideos.org Game Resources Section: http://tasvideos.org/GameResources/SNES/SuperCastlevaniaIV.html

https://www.youtube.com/channel/UCXNxXxnMxg5eQmUSiLGzLpQ This is the most up-to-date resource for strategy videos. I created a playlist of every video I could find from other channels as well.

Any% Theory TAS in 30:38: Theory TAS Notes: http://pastebin.com/GTrkhJqp Forewarning: These notes are very excessive and detailed, which will require a lot of time to study efficiently.

Hard Mode 'Learning' TAS in 31:58: