Just a small remark: the file for the original game jam version is called ‘Necrow co v4.4 jam build.zip’, but its title screen says that the version is 1.4; if the latter is correct, then the filename could be corrected.
(By the way, figured there would be a secret, yet finished on both ‘difficulties’ to see the difference, and now at the special level which is indeed hellish. XD Saving it for later, the final fight was already something, but this is gruesome!)