Wiki
Mechanics
Melee
Every run takes a gun and a melee weapon. The melee swing is on its own key, so it costs no ammo and no charge, and it stays useful all run because a kill with it pays extra XP and gold.
Perks like Follow Through and Bulwark only run for a few seconds after a melee hit, so they reward players who swing between shots.
Crouch slide
Hold crouch while moving and you slide. The slide opens with a kick of 1.6x your run speed on flat ground, more downhill, then bleeds off. Steering during a slide is slower than running, so aim it before you start.
Jumping out of a slide keeps the speed you built, which is the fastest way across a map.
Ground slam
Press crouch in the air, at least 1m up, and you drop straight down. The landing hits every enemy within 12m for 50% of your melee damage, reaching 7m above the ground for anything circling you.
It scales with melee damage, so the Melee Damage booster and melee mods make the slam hit harder too.
Dash
The dash throws you 3.3m in 0.14s, and you cannot be hit for 0.2s of it. That window is the answer to a boss volley you cannot outrun.
Dash charges, cooldown and distance are all boons the crystal cards and the skill tree can raise.
Secondary fire
Every gun has two firing modes. The primary builds charge on each hit, and the secondary fire spends it. Below 20 charge the secondary will not fire, and the bar on the crosshair dims to say so.
What the secondary does is the gun's own. The weapons page lists both modes for each of them.