Sorry for the late reply.
The line is a Line2D node. The start and end points are the player and mouse position respectively. It's kinda complicated to explain here in text but to bend it you first just check if its close enough to do it, and if it is you get the mid point between the player and hand and offset it a little to the right or left. The closer the player and hand are the bigger the offset. Again, it's kinda hard to explain.
And if you're talking about HYPER JUMP that's in 2D. To jump I just move the player's sprite node up and down and that makes it look like it's jumping.
Hope it helps.