Can you disable the blood on Nidhogg?

Solution 1:

It looks like the game was just updated, after 7 years:
https://www.techradar.com/in/news/the-best-fighting-game-of-all-time-nidhogg-just-got-a-major-update-7-years-after-launch

Unfortunately, instead of adding an option to not show blood at all, an option has been added that will make blood permanent during play -- once it's on the screen, blood will not disappear over time.

I hear your pain: I always appreciate an option to turn off (even cartoon, unrealistic) blood. However, knowing a bit about the spirit of this game, the blood is somewhat essential. I have actually had to stop playing this game for that and other reasons.

Also, there are now cats (apparently).