ULTRAKILL 73 - S.R.S. Cannon (Green Rocket Launcher Variation)
http://devilmayquake.com
Hold to charge, release to release. Less charge = less distance. Can be punched to boost, but will have a piercing limit unless bounced off an enemy first.
There's also some other stuff to it which you can see in the video, I'm not gonna type that all out.
Everything's WIP and liable to change.