Handcuff% is one of the misc. speedruns. To obtain the handcuffs, you must first beat the game then press 'New Game' you can tell that this is done when Doggo says something about Dejavu when you first talk to him. The handcuffs are in the first room of the school. They look like normal gloves and can be equipped like one. Different characters remark on how you are wearing handcuffs which can sometimes make the game longer. The handcuffs make you take 1 more damage from projectiles (bullets and homing missiles) and lasers. The default being 4 so you take 5 damage. It is also hard because you can't change into gloves which overall make the game much easier as each level of gloves helps reduce damage from projectiles and lasers.