Very quickly, it appeared obvious that Gravit would be impossible for the player to play without having a grappling hook to escape reverse gravity! But before making it, we had to create the ropes.
A rope allows the player to hold on it and swing like Tarzan or Spiderman. He/she can also climb it either ways, and even move onto a horizontal rope with the feet dandling in the air.
The grappling hook is a rope the player can fix anywhere. Thus, he/she can throw it from one branch to another and overcome many obstacles.