Thoughts: This was largely a boring map that had moments where it was trying to be funny but failed miserably. Even with the 'True' ending. Also, as mentioned before, the grappling hook was one player in making the map boring. This map wasn't fun to play at all and I only played through the whole thing in hopes that maybe, just maybe, there's a silver lining or that it would become better, it didn't as evidence by my post here.
Also, for the Giant Sapphire, I solved the torch puzzle and it didn't open. Which, this resulted in me going to the Merchant to buy a pick and get in by breaking blocks. Hell, don't even know WHY the guy is there in the first place.
A little recommendation: See if you can get people to test your map or even test it yourself during the early stages of creating what ever the hell you make next.