I thought the special effects were interesting, but all the crazy playing with perspectives and dimensions, and having things change so suddenly at random in the middle of action scenes killed any suspense for me.
As the world was always in flux, after the first few "oh shit he's going to be... ah no, the problem just dissolved into nothing/ twisted around him harmlessly/ was just an illusion" moments, I just stopped caring.
It all became just pretty colours and shapes whizzing around without any way to tell what mattered, how and why/ what was a threat/ what was really real, until after the action was all over and you could take stock.
And the ending seemed laughable to me, like an epic arse-pull without much conviction.
De gustibus non est disputandum