Just bought it. And I love it! 8 years, I've been waiting and it's finally mine. The combat is a little repetitive, but the world, the mystery, and the art is what enthralls me. If anything, I think it would be better without the combat, keep it as a first person adventure game. The puzzles, I think, are really well implemented and pretty easy to solve.
It's also frustrating to know that this is actually sort of how I imagined the space jockies and their story altogether, and it's actually a real shame this isn't what Prometheus was.