Death's Door is an action RPG about the character Crow, a bird and also a reaper of souls. It is an employee at the Reaping Commission Headquarters, a bureaucratic institution that tasks people like Crow with soul reaping while providing commissions on successful retrievals. At the start of the game it has to bring back a giant soul, but after defeating that demonic forest spirit it is attacked from behind and the soul is stolen. Crow cannot move on until the soul is secured, so there is no choice but to help the old reaper that tricked him and collect several other giant souls that may open the titular Death's Door where the soul is now held.
From a central location called the Lost Cemetery, Crow can access different areas leading to the three giant souls it needs to defeat and bring back to Death's Door. The character can be moved around freely and has two melee attacks along with a ranged attack with limited ammo. Eventually five different weapons can be unlocked and they can be changed on the fly. They vary in style, appearance and statistics such as damage, swings, range and swing time. The regular melee attack is for quick hits, while the second one can be charged or a strong attack or is executed following a dodge roll. Ammo for the ranged attack can be found through items or by hitting enemies. Melee, but especially ranged attacks are often used to solve puzzles such as hitting items or setting them on fire from a distance. Many areas require environment based puzzle-solving to collect items and progress. There are many enemies to defeat along with several larger boss fights that require figuring our patterns, dodging and sometimes puzzle-solving to discover weaknesses.
There is a checkpoint and fast travel system through doors. At certain locations a door can be unlocked that leads back to the central Hall of Doors at the Reaping Commission Headquarters. From there Crow can quickly return to any area at any time or choose another door. When Crow dies he returns to the last unlocked door. At the HQ there are characters to talk to, puzzles to solve and the Soul Vault where four characteristics can be upgraded several times: strength, dexterity, haste and magic. Each upgrade requires soul energy collected by defeating enemies. Health can be replenished by picking up seeds and planting them in specific pots. Upon consumption all health is restored, but this can done only once at that pot until Crow dies or leaves the area to return.
The game also contains many secrets and optional collectibles. Over time three additional magic items are unlocked as additional ranged weapons that can be switched on the fly similar to melee weapons. The new magic types often open up additional paths or secrets in previously explored areas metroidvania-style, or allow Crow to pursue a new path or open a new gate that was previously locked or out of reach. There are several characters to talk to and the game contains many humorous elements.