Too many loose threads
1. The 'Dutch Hunters'? Heavily discussed before entering the campsite. Then forgotten. Was the shirtless guy supposed to be a dutch hunter? The hunters ended up having zero impact.
2. Is the 'bad guy' supernatural? Or the work of humans? Why would ghosts use that patented spot light? Did ghosts bury that large tin chamber? These seem to be man-made objects
3. Nothing from or about Ross's uncle after we hear his story
4. No confirmation that they did or did not time warp
5. Returning the gold-infused quartz was so important but didn't change their fate at all
6. Does Ross even die?
Maybe these questions were left open-ended to add to the suspense, but to me the movie has too many plot elements to tie neatly together. It's like if Lost ever didn't have a next episode.