The alien looking terrain and pretty lighting drew me into playing this game. I didn't get the fun of exploring from the core mechanic because it was difficult to use the grappling hook, jumping over blocks was annoying, and the player controller needs more polish. With the hook, I can never tell when I am in range, and I found the left and right click functionality to be confusing. The few moments where I was swinging fast through caverns or falling into the ocean were exciting. When I was drawn to something in the terrain, it was either a cave, high spot, or a spot that might be fun to swing off of. The visuals are beautiful and simple, which I personally enjoy seeing in video games.
I think a jet pack or super jump ability would be cool. Portals gates would be cool too, maybe they have an emission material that can be seen from the distance. They could be color coded. Perhaps the player can place down portals. What if giant flying whales wondered the space and you ride them. More gadgets would be cool because that would help me role play as an agent. Maybe a x-ray machine that can help me see hidden objects or caves. Check out the gadgets that ghost investigators use. What about a long range zip-line gun?? That would be fun to zip across large valleys and save time.