I did fix multiple ufos making the sound at the same time in the last update, though if i find more instances of that problem i'll try to fix them in future updates.
Could you tell me which sound effects by themselves felt off to you?
Viewing post in Touhou Lunar Invaders jam comments
I think in particular the sound effect when the player shoots was a bit off to me since it's pretty bass-y. (Is to say, it's at a low frequency, I believe would be the technical way to put it.) On headphones I found it pretty noticeable and hard to drown out. I think it could be a bit subtler because it's basically constant (since you're mostly always shooting).