I really enjoy your painless smile series. (especially that classic music, I'm glad you keep it!) And I'm also glad to this installment has even more improved visuals and new features. However there are some major issues(at least for me) in some stages:
Corpses hanging stage: If you run out of ammo then this level is impossible. All enemy have range attack that you can't dodge so it's impossible to use katana. Perhaps that's why we have more starting ammo in this game than in previous games, but I'd still like to have some way to conserve ammo in early level.
Black demon stage: For some reason the screen always turns blue whenever the next level is this stage and I have to refresh and click continue to start this stage. The black grass make it hard to see the enemy.
Cherry tree stage: Obviously the best stage. Doesn't have big issue although it took me a while to figure out some enemy can throw their heads now.
I would suggest making the projectiles from range enemy dodgeable. Also maybe a bestiary that explain which enemy can explode or do range attack can be useful for new players. I love this series and I hope my opinion can make it better.