No shame—the game is super difficult (partially by design, because I think it's at its best in the mayhem, but this was also largely a result of me having a terrible gauge on the matter).
You can use the in-game menu (press M to open it) to skip around, and the points are based on how far you make it through each level, so it's not really the intention that people will complete every single one. Based on your experience though, I think that's not really clear, so I've added an explanation (and warning about difficulty) at the bottom of the itch page.
Thanks for sharing your experience! I encourage you to check out level 9; I think you'd enjoy the spectacle :P, though I can't promise it will be any easier.