That desire to create something different is going to serve you well in the writing process; hang on tight to that.
But first, let’s consider a couple of questions. WHO IS YOUR INTENDED AUDIENCE for this film? Are you thinking yours would be an ‘art house’ crowd? Maybe you’re planning an experimental film? Or are you hoping for a mainstream distribution deal? The closer your intended audience is to the mainstream, the more thoroughly your story should be grounded in the standard 3 act structure; beginning, middle and end (or resolution).
Next, let’s look at your bias against the 3 act structure. It IS true some really terrible movies have been created within the context of this format. But WOW, what about the really inventive films that have also adhered to it? Films like 'Being John Malkovich, Juno, The Fall, American Beauty' are all firmly grounded in the 3 act structure too. What gives?
Many beginning screenwriters lay some really BAD MOVIES at the feet of the 3 act structure. But writing screenplays is a lot like writing sonnets (you know, Shakespeare - iambic pentameter) in that it’s a strict format that can produce some absolutely timeless writing… like Shakespeare’s “Shall I Compare Thee to a Summer Day.” Or the really horrible assignment I wrote my sophomore year in college. I had the format down pat, but Shakespeare would have rolled over in his grave.
Great sonnets, like great screenplays, challenge writers to search for a completely fresh aspect on a timeless theme - and then test their inventiveness in pouring their story idea into a ‘jug’ of specific proportions. The bad movies you’ve seen aren’t a result of the 3 act structure - but a result of the lack of skill or persistence on the part of the writer.
I hope this helps. And I do wish you luck with your screenplay - and let me know when you’ve completed your script. I’d love to read your work!