Thank you so much for this feedback, it was pure gold. It only reinforces the importance of testers throughout the development of a game: During development, I played my own game so many times and got so used to how it worked that somehow I forgot that it could be harder - or sometimes even unfair - for other players at some points like the canon. I only had 1 day and a half to finish the game because I started late, so the lack of feedback from others really shows up, right? You are absolutely right about both cannons and laser turrets: not only they were too fast, but they were also missing audio cues whenever the player was next to them.
I just updated the game with nerfed cannons and more cover options for the second level, and some reduced visual stage noise for stage 3 as well as blast sfx for them when the player is near (otherwise it would be playing sfx all around), so please try it once more if you have the time, it should be less absurd now. I hope it makes amends with your score.
Once again thank you for your feedback. You asked me not to take your review too personal, but I think productive feedback like yours is exactly what we need to improve. Cheers!