Pacific Rim should never have been made. Oh, that it was a success, and enough so to inspire a sequel, is a merciful miracle, but to get del Toro's love letter to giant robots and old kaiju movies we had to essentially bid farewell to At The Mountains Of Madness. Guillermo del Toro's attempt to adapt HP Lovecraft's classic novella about an ancient civilisation hidden beneath the ice of Antarctica had a lot going for it: James Cameron had promised his pioneering 3D special effects technology from Avatar, and signed on as a producer; Tom Cruise was also in as the star, despite it being an uncharacteristically non-blockbuster project. It was that which ultimately sunk the film. It's a dark, scary exploration of humanity and ancient evil. Del Toro wanted it to be R-rated, full of gore and unpleasantness, but the scale of the story required a huge budget, which likely couldn't be recouped by such a weird film. Lovecraft has inspired parts of every del Toro film, so to see him finally tackle that influence head on - and with some amazing special effects and actors - would have been incredible. But it looks like it is never to be. What other Guillermo del Toro projects remain unmade? Share any more we missed down in the comments.