If we stick to the strict definition of unique, a book can't be "somewhat unique" or "very unique". Unique means one of a kind.
Of course there are very few things that are unique. Most are variations of what already exists. However, from time to time I meet an author who says their book or screenplay really is unique--nothing like it has ever been done.
If that's true of what you are writing, prepare for an uphill battle.
One of the first things a publisher asks is "what are some comparable books?"
It may surprise you that if you say there aren't any, that's a negative as far as the publisher goes. They know that something really new will require too much work to explain to an audience. They prefer saying "This is just like (name of best-seller) but even better."
If you want to attract a publisher, put some comparables in your query letter or proposal and explain why yours is similar and also how it's (a bit) different. Naturally, choose books that have sold well.
If you self-publish you'll have to make the same thing clear to readers.
If you do have something unique, congratulations. The odds are it will be a huge success...or a huge flop. It's possilbe that there hasn't been anything like it because nobody actually wants anything like it...or because they didn't know they wanted something like it but now that it exists they can't wait.
(Want to be even more creative? Get a copy of the colorful, fun to read, and highly useful book, CREATIVITY NOW, published by Pearson and available from Amazon or your other favorite bookseller.)