I enjoyed playing this game. Here is my feedback:
At first I could not figure out the controls, I tried clicking the buttons on the left to equip the different fruit. Then I tried shooting fruits but I was shooting them backwards... to me it felt like the controls were inverted. I was interpreting it more as throwing fruit (launching it with your mouse) rather than shooting fruit (like a sniper).
I couldn't figure out how well I was doing. In my first attempts I thought the bar above the ninja was his health bar but now I think it shows when the ninja is vulnerable. I also thought the purple bar was his health or something. Then I thought I had to fill this bar to the max to win. I was a little bit confused.
Also, the slow motion affects UI elements. I think it is possible to make certain nodes ignore the speed change in Godot but, if it is not, you could also try changing the speeds of the tweens in scripting to compensate.