What makes Pixel Flow fun?

Hello!
This is a different post than the rest, I hope that's fine.
I recently came across Pixel Flow and there are some interesting things in this game that are new and enjoyable and I am interested to hear your opinions about them, for example having 5 inventory slots, but you can play with 9 shooters at once, it's a genious idea because it motivates risky play while also being forgiving, when I make a mistake, I get the chance to play more risky to fix my mistake, what do you think about this mechanic?
What else does Pixel Flow offer that keeps you coming back to play more?
Also what are some annoying things that bother you while playing? I think some levels have extremely similar colors and that is resulting in me making mistakes without realizing and it is somewhat bothering for me