Undefined Fantastic Object

Undefined Fantastic Object features three playable characters (Reimu, Marisa and Sanae), each with two weapon types. However, unlike Mountain of Faith and Subterranean Animism, the spell card (bombing) system from the older games (such as Perfect Cherry Blossom and Imperishable Night) has been reintroduced. Point value penalties for dying have also been removed. There are 4 levels of difficulty: Easy, Normal, Hard, and Lunatic. Each difficulty level features differences in the number of bullets fired by each enemy, rate of fire, variations in the bullets' pattern of movement, and the number and type of enemy Spell Cards used.

A character's "shot" is the player's primary method of attacking enemies. The shot's attack area and behavior vary depending on the character and attack type the player has chosen.

Like previous Touhou games, there is a line most of the way up the screen called the point of collection. If a character is moved on or above this line, all items on the screen will be drawn to that character. Unlike previous games, it is not necessary to have full power or focus to use the POC because it is always available.

Grazing is the act of positioning the character's hitbox close to the bullets without getting hit. Similar to its older games, grazing is one of the most effective ways to rake in high scores—if done accurately and effectively. For every 10 bullets grazed, the point item value increases by 10 points. Grazing also works during invincibility periods, such as resurrection or bombing, unless the bullets have been destroyed. While grazing in the short term is minimal, it can boost point item totals by a large scale. Being able to calculate remaining point items in the entire game ahead of time is a rare mathematical feat, but it helps to determine whether or not grazing is worth it in certain situations.

Undefined Fantastic Object re-introduces bombs with distinctive visual styles that differ between characters, and even between shot types for the same character. A character's "bomb" is the player's limited-use method of getting out of difficult situations. A bomb's attack area, duration, and power vary depending on the character type and attack type the player has chosen. It typically deals heavy damage to every enemy it touches, in addition to canceling out any bullets in the bomb's way. The player's character becomes invincible during the bomb's use and for a short time after the bomb's effect wears off. At the beginning of the game (and any time the character revives), the player starts off with 2 bombs. The player can increase their bomb Stock by collecting bomb pieces (3 are needed for a bomb) or bomb items. Green UFOs drop a bomb piece when defeated, and a full bomb when their score multiplier is full. The player can carry up to a maximum of 8 bombs at a time. If the player receives a bomb when they already have the maximum, that bomb will be lost. Unlike previous games, if the player loses a life, the bomb counter only resets to default value of 2 if the player has less than 2 bombs—which means the player can always utilize all of their accumulated bombs. Also, unlike every Windows game up to Subterranean Animism, bombing does not auto-collect every item on screen.

Some enemies will have small green UFOs circling above them. They drop a small UFO after being destroyed, and some stage mid-bosses will drop 2 small UFOs after their final attack is defeated. The small UFO will fly around the screen. They come in red, blue and green colours. There are two types, blinking and non-blinking. The blinking UFO will change colours every few seconds. However, keeping the character's sprite in close proximity to the UFO will prevent it from changing colors. The other type of UFO will stay a single colour. These non-blinking UFOs are not random, so their positions in the levels can be memorized to further advantages.

Collecting three UFO items causes a large UFO enemy to appear on the screen. Three of a specific colour of UFO will summon a big UFO of that colour, while collecting one of each will summon a flashing big UFO. If the player has picked up two UFO items of the same colour and then picks up an item of a different colour, the first item in line will be replaced by the colour of the item picked up last. If the player has two UFOs, a UFO of the color that will result in summoning a large UFO will be surrounded by a flashing pentagon so the player knows what type to collect without having to look at the bottom-left corner. Each summoned UFO has a life bar and timer for how long the player has to defeat it. At about two seconds left on the timer, the UFO will start ascending to leave the screen; it is important to defeat it before it leaves. Otherwise, all the items it has sucked in will be lost. If the UFO is on the screen at same time with a boss, it will fly away even if there is time left; however, in the case of mid-bosses, the UFO will stop flying away if the boss is defeated in time. In-game dialog will make summoned UFOs explode.

Throughout Gensokyo, rumors have been spreading since early spring about a strange, flying, treasure ship. With the help of Sanae Kochiya, the girls take off to Gensokyo to find the ship and plunder its treasures. During the high-speed chase of the "UFO", the player confronts Nazrin, who has come from the flying object looking for something in particular. She insists the ship does not exist. The player then encounters Kogasa Tatara, whose only purpose is to frighten the girls away.

As the player catches up with the ship, Ichirin Kumoi and her familiar Unzan appear, complaining about fairies and humans who have been pestering them. She says the "ship" is actually a remodeled building that has given the power to fly. Ichirin Kumoi also says she is trying to revive someone. The fragments—the UFOs that the player has been collecting—are necessary for this purpose, but rather than handing them over, the player defeats the pair and enters the ship.

Inside, the player finds a strange, flying object that promptly attacks and leaves items. Ignoring this, the player finds Captain Murasa, the youkai ghost captain of the ship. She tells the player the ship is heading for Hokkai, a world connected to Gensokyo that is located on the outer edges of Makai. Because the player entered the ship with enough fragments in their possession, it has already begun to enter Hokkai.

Before long, just outside Hokkai, the player again encounters Nazrin, who has found what she was looking for—the Vaisravana pagoda. After defeating her a second time, Shou Toramaru appears. Now the pagoda and the fragments are together, the revival can begin. Shou tells the player they are trying to revive a "saint" who has been sealed for many years—a person who was punished for helping humans and youkai. After defeating Shou, the player chooses to help revive this person.

The final confrontation happens deep inside Hokkai, where Byakuren Hijiri has been unsealed. The player must exterminate youkai (or, in Marisa's case, to prioritize protecting humans). Byakuren disagrees—she is an ally to both and treats both equally. The player defeats Byakuren in a long battle, and the story ends on peaceful terms as she and Murasa cruise around Gensokyo in the ship before settling down and rebuilding Byakuren's original temple.

However, the mystery of the UFOs is still solved. Upon opening one of them, Marisa discovers a snake and the UFO turns into a piece of wood. The girls take off once again into the night sky to investigate. Kogasa reappears, trying to surprise the player. The strange flying object appears again and transforms into a youkai named Nue Houjuu, who disguised the fragments. Only the player saw the UFOs as UFOs—the enemies the player fought against knew they were actually pieces of the ship. After defeating Nue Houjuu, she says she was originally trying to obfuscate Murasa's efforts to revive Byakuren, but the player caught her interest so she helped the player too.

Reimu (left) and Marisa (right) from Undefined Fantastic Object.

Playable characters:

• Reimu Hakurei - The miko of the Hakurei Shrine. She sets out to investigate the treasure ship thinking it is yet again the work of yōkai.
• Marisa Kirisame - A magician who lives in the Forest of Magic. She seeks the treasure ship simply because it piqued her curiosity.
• Sanae Kotiya - The wind priestess of Moriya Shrine who is playable for the first time in Touhou. She is still adjusting to life in Gensokyo, and tries to prove herself by setting out to find the treasure ship under the orders of the goddesses she serves.

Bosses;

• Nazrin (ナズーリン): Stage 1 boss and stage 5 mid-boss. Being a leader of mice and a natural dowser, Nazrin was commanded by Ichirin to search for the shards that fell from the sky, but her dowsing rods brought her to the humans instead.
• Kogasa Tatara (多々良 小傘): Stage 2 boss and extra stage mid-boss. Kogasa was once an umbrella who was forgotten for a long time and thus became a kasa-obake. Being bored and lonely, she tries to perfect the art of scaring humans.
• Ichirin Kumoi (雲居 一輪): Ichirin is the stage 3 boss who is accompanied by Unzan, who also participates in battle. Ichirin, by her own accord, is the guard of the large ship in the sky. She seems to be collecting UFO-shaped shards to revive Byakuren Hiziri, her master, whom she refers to as "sister."
• Unzan (雲山): Ichirin's companion in stage 3. Unzan is a nyūdō made out of clouds. He is a stubborn, quiet old man who is gentle at heart.
• Minamitsu Murasa (村紗 水蜜): Murasa is the stage 4 boss, who is a funayūrei - a spirit of a human who fell off a ship and drowned in the past. As the humans feared her, their fears turned her into a yōkai. She pledged herself to saving Byakuren, riding the ship she created.
• Shou Toramaru (寅丸 星): Shou is the stage 5 boss, representing good fortune as an avatar of Bishamonten. She was chosen by Byakuren to have the mountain yōkai gather faith in exchange. When Byakuren disappeared after a few hundred years, the temple was in great disarray, and all of her friends who were sealed into the Earth returned. Shou, not wanting to run away or have any regrets, told Murasa and the others how to lift the seal.
• Byakuren Hiziri (聖 白蓮): Byakuren is the stage 6 boss. She had a younger brother, Myouren Hiziri, who taught her Buddhist magic, but died earlier than her. This made Byakuren fear death greatly, and obtained the power to regain her youth. However, it was considered black magic rather than an art of Buddhism. Ichirin was her servant, while Murasa pledged herself to saving Byakuren.
• Nue Houjuu (封獣 ぬえ): Nue is the extra stage boss, also appearing as a sphere of light in stages 4 and 6. She is a nue- a very mysterious yōkai who flies through the night sky. Despite being non-human, she was defeated by humans many times in the past, but the accounts of her appearance vary. However, those were all made up, because her form is never seen to anybody but herself. She merely enjoys frightening humans and their imagining of strange things from afar.

• Rensenware, ransomware requiring victims to play Undefined Fantastic Object in Lunatic mode and get at least 200 million points

• Official website (in Japanese)
• Undefined Fantastic Object on Touhou Wiki