As someone who 100%'d both Sekiro and Nine Sols, I wasn't able to get past half of Komachi's health bar after 10 or so tries. The concept is great, but as a Jam game it's clear there was no time for the combat to receive the full quality pass that it really needed.

Youmu's attack is not only a somewhat lengthy animation but is also not cancellable. You can't really fight offensively because you'll continously get hit due to being stuck in your attack animation and be unable to block. Not only that, enemies (at least Komachi) don't have properly telegraphed attacks, they largely snap from stances to attacking w/ active hitboxes instantly. These two things makes the combat not work or flow properly, and it's exacerbated by only being able to get hit 5 times total before losing, no matter how small the mistake is.

One more smaller thing is that Youmu's attack has surprisingly little range. You get pushed back when blocking, but you also do not move forward while attacking, so the attack often ends up out of reach from the enemy, further slowing down the combat.