The The Gage Ninja Pack Add-on for Payday 2: Crimewave Edition has 4 achievements worth 90 gamerscore.
Kill 100 enemies in a single day of a heist with the Kross Vertex SMG.
Finish a single day of a heist in stealth using only the Shuriken and killing at least 4 enemies.
Get eleven kills with the Lebensauger .308 Sniper Rifle without reloading it.
Have at least 3 enemies poisoned at the same time with your poisoned weapons.