Rising from her slumber, a young girl named Rose finds herself in an old castle frozen in time and devoid of color. Attached to her waist is a mysterious rose capable of absorbing the color red. As she made her way through the castle corridors, she finds a giant creature with a swirl mark on its abdomen. While initially afraid of the creature, she warms up to it when it goes out of its way to protect her. Forming a bond with each other, Rose and the Giant decide to travel through the castle, hoping to find out why she has this rose and answer the many mysteries surrounding this castle.
Players can switch between Rose and the Giant. As the fragile Rose, players use her ability to absorb and imbue objects with the color red. Absorbing red freezes objects in place while imbuing objects with red grants them movement, allowing them to be interactable. The more sturdy Giant is capable of surviving any kind of a hazard, allowing it to move through places too dangerous for Rose, and is strong enough to lift and throw heavy objects. Players need to make use of both of their abilities to overcome the many obstacles in the castle.
This game provides examples of:
- Bittersweet Ending: The True Ending. Despite all of Viola's efforts, she became an avatar of hate and died as such, never gaining any kind of happiness or closure. Rose and Blanc also die, possibly crushed by the crumbling castle despite the Giant's best efforts to protect them. However, the two have reconciled, and are playing together again in the afterlife, free from the curse of thorns.
- Bloodier and Gorier: Even by the standards set by htoL#NiQ: The Firefly Diary and Yomawari: Night Alone, this takes the cake. Blood is a major part of the game and unlike the previous two games, A Rose in the Twilight is not afraid to actually show Rose getting eaten alive or killed by torture devices.
- Downer Ending: The Bad Ending. Upon finding Rose fastened above a chandelier, have the Giant break the chandelier's chains to save her. It turns out that the one the Giant saved was actually Blanc and that she placed Rose below the chandelier. Having mistaken Blanc for Rose, the Giant ends up inadvertently killing Rose. Blanc lets out an evil giggle toward what remained of Rose before leaving the castle with the Giant.
- Evil Twin: Rose encounters a girl who looks like her, but her clothes and crown are tattered. Her name is Blanc and her memories reveal that she's possibly her twin sister. She was attacked by thorns, but, despite her pleas for help, Rose too afraid to save her, causing her to get cursed by the thorns. When they meet again in a dungeon, Blanc, filled with rage over being abandoned, attacks Rose with her thorn vines, inflict the curse of thorns on her as well.
- HeelFace Turn: During the final boss battle, when Viola freezes all the thorns thrown at her by the giant, Rose imbues Blanc's rose with the color red. Blanc then imbues the thorns with color, allowing them to fly directly at Viola and defeat her once and for all. The twins finally reconcile and are seen playing together in the afterlife.
- I Choose to Stay: After busting the thorns blocking the exit, Rose and the Giant depart, but after she accidentally leaches the color from a plant, she and the Giant elect to reblock the exit and spend the rest of Rose's life in the castle.
- Justified Extra Lives: Rose's ability to return to checkpoints after death is explained in a scroll. Those plagued by the curse of thorns have Resurrective Immortality, allowing them to reappear in certain areas after death with virtually no injuries no matter how gruesome their death was.
- Load-Bearing Boss: Viola is the source of the castle being entirely stopped in time. Killing her allows time to resume... on the collapsing castle that her previous use of her powers caused.
- Man-Eating Plant: There are several Venus flytrap-like creatures in the castle, and they will eat Rose alive if you get into their mouths. Luckily, they also eat bugs and luring one into their mouth will make them disappear and clear a path for Rose and the Giant.
- The Many Deaths of You: There are just so many ways for Rose to die due to her being so fragile. Falling great distances, getting impaled, or getting eaten are some of the standard deaths, but she can also kill herself with a press of a button and unlocking the castle's wings require her to use torture devices on herself. You'll be watching her die a lot. As a consolation prize, you get trophies after dying a certain amount of times.
- Morality Chain: Viola's lover was the only person left who could keep her sane. When the Religious Order had him killed, she gave in to her vampiric urges and lashed out at everyone.
- One-Hit-Point Wonder: Rose is sadly a fragile little girl so any obstacles like giant thorns or long drops will kill her instantly. It's something to keep in mind when having the Giant carry Rose as she is not able to survive the obstacles that he can simply walk through.
- Our Vampires Are Different: Unlike most classical examples of vampires, the vampires in this game have floral-based powers, attacking mostly with thorny vines. Viola's outfit also goes against traditional vampire outfits, having bright shades of pinkish-red instead of the traditional black. It turns out anyone affected by the curse of thorns is a vampire, making Rose and Blanc vampires as well.
- Nigh-Invulnerability: With exception of bottomless pits or one exceptionally long fall, there is absolutely nothing that can damage the Giant. Thorny vines, falling debris, and giant drops do nothing to stop him. At best, all they do is push him back a bit.
- Press X to Die: Holding the Select button on the Vita (or the equivalent on the PC) will kill Rose and send her back to the nearest checkpoint; the game's tutorial on this ability happening in an area where Rose cannot escape or proceed without killing herself. This is useful if you find yourself in a situation in which it is impossible to progress. Also, having Rose use various torture devices on herself is required to progress through certain sections.
- Resurrective Immortality: If Rose dies, she will simply return to the nearest checkpoint as if nothing happened. Unlocking new areas requires her to make use of her resurrective abilities by using the nearby tortures devices on herself. Viola and Blanc have this ability as all three of them are vampires.
- Spiritual Successor: To htoL#NiQ: The Firefly Diary. Like its predecessor, it features a young girl with plant-like features being guided by a mysterious creature through ruins filled with danger. She also encounters a girl who looks like her who has become vengeful due to being abandoned and wants to kill her.
- That Man Is Dead: Viola more or less quotes the trope in her final diary entry. After the Religious Order executes her lover, she declared that the inquisitive Viola was no more and became the very thing she and the Religious Order feared.
- Well-Intentioned Extremist: For centuries, an evil creature with the power of thorns wreaked havoc across the land, only being stopped by divine intervention (In the form of the Giant). Naturally, to prevent such a creature from rising to power, the Religious Order was formed to destroy those cursed by thorns. However, Viola was just adamant about not becoming a vampire as they were, searching desperately for a cure. It was their callous actions, especially murdering her lover, that drove her to madness and created the very thing they both feared.
- Woobie, Destroyer of Worlds: Viola. All she wanted was to be with her father and lover, and nothing more. Unfortunately, she was cursed by the thorns, and the Religious Order shows no mercy to those who are cursed. Despite her best efforts to find a cure and her lover trying to protect her, the Religious Order finally captures her and her lover is killed for aiding her. The latter becomes the last straw, allowing her hatred to consume her and kill all who stood in her way.