Hoarder

Hoarder is an unlockable achievement in the exclusive Xbox 360 port for the classic Doom game. It is unlocked when collecting all items in one of any level.

Strategy
There is an easiest way to unlock this achievement in few levels. In Episode 3's E3M1: Hell Keep level for example, there are 6 Health Bonuses and 2 Armor Bonuses to find.

Note that the achievement cannot be unlocked in multiplayer mode.