"and you won't be able to re-submit this item again".!

I wanted to upload my first project, it is quite complete and efficient, but they tell me this, and it worries me

Thank you for your submission. We have completed our review of “Name” and unfortunately we found it isn’t at the quality standard required to move forward, and you won’t be able to re-submit this item again

Demo: https://project-ufo.codekitstudio.com/

Not sure about the coding but the design is not good enough.