The Episode 4: Metamorphosis Add-on for Resident Evil Revelations 2 (Xbox 360) has 6 achievements worth 320 gamerscore.
Clear Episode Four.
Defeat six or more Glasps in the monument in Claire's Episode Four, on Normal difficulty or higher.
Clear Episode Four in Countdown Mode.
Clear Episode Four in Invisible Mode.
Get all medals in Episode Four.
Complete both routes through the landfill in Barry's Episode Four.