The Operation: Hydra Title update for Halo: Spartan Assault (WP) has 5 achievements worth 50 gamerscore.
Complete Operation F
Destroy all Mega Turrets with the Grizzly tank in Operation F, Mission 2
Earn all Gold stars in Operation F
Complete Operation F, Mission 4 with the Blind and Thunderstorm Skulls active
Complete all Operation F mission challenges