Darkwing Duck (1992) is a platformer somewhat similar to Mega Man in gameplay and difficulty. The arrow gun allows the player to climb up walls and use creative shortcuts so that the absolute shortest route can be taken. In case you are wondering why the character keeps on jumping so much, it is because he has to wait a short amount of time before being able to walk. With constant jumping these stops can be avoided.
This run by DreamYao, J.Y, and aiqiyou saves 16.39 seconds over the previous run thanks to improved jumping and arrow techniques. For more details, you can read the authors' comments.
Watch this run being played back on a real console.