Do a rocket jump just like Soldier from TF2, but with a flashlight.Also the dark attack is kinda a grappling hook, except the pulling force is harder the closer you are to the walls.
Thanks for the help. It's a cool game. The feeling of the gun is nice once you understand how it works. The latest additions really improve the game.
However I find it a little too difficult for me. Despite many attempts, I always die before the end.