The The 2020 Update Title update for Out of Ammo has 12 achievements.
Complete the Tutorial
Beat Wave 20 on the Forest Mission
Beat Wave 20 on the City Mission
Beat Wave 20 on the Desert Mission
Beat Wave 20 on the Winter Mission
Beat Wave 20 on the Port Mission
Beat Wave 20 on the D-Day Mission
Beat Wave 20 on the Canyon Mission
Beat Wave 20 on the Contact Mission
Beat the Plane Crash Challenge Mission
Beat the Penthouse Challenge Mission
Beat the Sniper Challenge Mission