Ori and the Blind Forest: Definitive Edition is a platform-adventure Metroidvania game developed by Moon Studios and published by Microsoft Studios. The game was released for the Nintendo Switch in September 2019. In the game, players assume control of Ori, a small white guardian spirit, and Sein, the "light and eyes" of the Forest's Spirit Tree. To progress in the game, players are tasked to move between platforms and solve puzzles. The game features a save system called "Soul Links", which allows players to save their progress at will with limited resources, and an upgrade system that gives players the ability to strengthen Ori's skills.
Ori and the Blind Forest: Definitive Edition is a 2D platform game. The player controls Ori, a white guardian spirit of indeterminate gender, and Sein, who is the light and eyes of the Spirit Tree. Ori can jump, climb, and use other abilities to navigate. Sein can shoot Spirit Flames to combat enemies or break obstacles. Ori is required to interact with their environment as they jump from platforms and solve puzzles. Ori is faced with enemies while making their way to restoring the forest. The player helps Ori collect health shards, energy shards, new abilities, and upgrades. The game world unfolds to the player in the fashion of a Metroidvania, with new abilities allowing the player to access previously inaccessible areas.
In addition to save points scattered in the game, players can create "soul links" at any time they choose to serve as checkpoints. However, soul links can only be created using energy cells collected during gameplay; the needed energy is not in abundant supply, forcing players to create them only when necessary. The player can gain ability points to buy various perks and upgrades, such as increasing the damage of Sein's Spirit Flame. These upgrades can be bought anywhere a soul link has been created and if the player has enough ability points to buy the skill they desire. An ability point is gained when Ori collects enough experience by killing enemies and destroying various plants. Each skill must be bought in sequential order from one of three ability trees to allow the next, more expensive skill to be accessible.
The voice of the Spirit Tree in the forest of Nibel narrates the story of when Ori, a white guardian spirit, fell from the tree during a storm as a newborn and was adopted by a creature named Naru, who raised Ori as her own. A cataclysmic event soon makes all of the forest wither, and Naru dies of starvation. Newly orphaned, Ori was left to explore the forest on their own. After collapsing near the Spirit Tree and being restored to life by it, Ori later meets Sein, a being in the shape of a small blue orb, who both guides Ori on their adventure and attacks enemies. To restore the forest, Sein guides Ori to recover the light of three main elements supporting the balance of Nibel: Waters, Winds and Warmth.
Ori and Sein come across two beings in their quest: Gumo, the last survivor of the spider-like Gumon clan and whose home supports the Wind element; and Kuro, a giant, shadowy owl who is hostile toward Ori. Her hostility and the forest's cataclysm are explained in flashbacks. When Ori was lost, the Spirit Tree released a flash of light to look for them, which killed all of Kuro's recently hatched offspring. Determined to prevent this from happening to her yet unborn child, Kuro took away the core on top of the Spirit Tree, which is actually Sein. Without the Spirit Tree's support, the three elements cannot be sustained, and Nibel lost its balance. As the element of Wind is rekindled, Gumo, realizing what Ori and Sein intend to do, uses his clan treasure that stores the light from the Spirit Tree to revive Naru, and takes her to where Ori is.
After the final element, Warmth, is restored in the volcano Mount Horu, Kuro captures Ori and Sein as the fire from Horu starts to spread. Naru, who had been separated from Gumo, arrives to protect Ori from Kuro. Kuro softens, remembering the pain of losing her children. As the fire spreads and is about to reach her remaining egg, Kuro takes Sein back to the Spirit Tree, which emits a flash of bright light that dissipates the fire and restores the forest, but Kuro is destroyed by the light. Time passes as the forest begins to flourish once more, and Ori is shown sitting on a log watching new spirits being born in the field at the foot of the Spirit Tree. Gumo and Naru watch together from afar, before the latter goes home, where Kuro's last egg now rests, just in time to see it begin to hatch.