The player character, a dog, can learn a combat technique called Brown Rage, allowing her to take an exploding dump that damages enemies. Learning or using this technique is not required for progression.
The Ichiro is a rare enemy type that resembles a great white shark wearing armor, and it first appears as a mini boss whose defeat is required to proceed. After that, it may rarely appear as a regular enemy encounter, which can be fled from.
Many ponds, rivers, and streams are dotted around the landscape, large parts of the game take place on an oceanic coastline, and there is an icy lake at the end of the game.
The game centers around a highly fictionalized version of Shinto mythology and folklore; the protagonist is Amaterasu, the Shinto sun goddess, and several other Shinto deities make appearances. A major theme of the game is that bad things are happening because the people have stopped believing and having faith in the gods.
The player is required to visit the Dragon Palace, which is located at the bottom of the ocean. The locale is bright and friendly, and the player is able to navigate the area by walking normally rather than swimming, making the area more akin to a regular surface location with bubbles and a slight filter in practice.
The player character, who is a wolf, can get slapped around by certain character out of battle. Most notable is by Mushi's Mama who punishes anyone who messes with her turnip garden with a smack and has been implied to do it Hayabusa, Mushi's dog, when they to try just that.
Not only did an animal character die in the opening, it's also mentioned another character's old dog died protecting their owner's father. Other than that, the same character who dies in the opening show up before they got hurt due to time shenanigans and more realistic still 2d art depicts them bleeding.
There's one main boss (Spider Queen) and a recurring mini-boss (very similar to the spider queen) that pops up a few times through the game, and one level (Emperor's Garden) with many, MANY spiders (platform spiders, swinging spiders, blocking spiders, they're everywhere).
To address another comment, the sidekick, named Issun, is NOT a bug. He is a tiny (one inch) person called a Poncle wearing a hat that LOOKS like a bug, but in his character portrait he is a silhouetted humanoid. All Poncles wear bug hats. There are also regular bugs.
What everyone's saying is a possession was actually a demon taking on the form of someone who died. You end up finding their corpse while the demon's still active
It's possible for the player character to drown, but you never see the character sink or anything. The player just stops moving and then is transported back to land.