Undertale Yellow Flowey Fight Simulator

Keys

Arrows move the heart. Z interacts. X dashes. Press Play, then click inside the frame. Until that click, the keys do nothing.

A phone cannot play this. The fight wants a keyboard the whole way through.

If the battle stutters, RatchetJobaria points players to TurboWarp for the same project. Players on the Scratch project have posted full clears. The same thread also describes lag and bugs in the specimen phases, including clay.

Six petals

The fight in the frame is the second phase. Players call that form Meta Flowey. Undertale Yellow does not print the name on a title card. It comes from the fight's code.

The bullet box fills the lower half of the screen, and Flowey hangs over it. The SOUL is yellow, so it shoots. In this project, X is the dash. Afterlife plays under this phase, and each petal brings its own specimen track.

Six petals come in this order: patchworked, organic, clay, paper, polygonal, mechanical. Shoot the red weak point to enter one and to finish it. Between petals, gray attacks run for about 25 seconds. Clearing a petal heals 60 HP. In Undertale Yellow, the first petal unlocks the dash for the rest of the battle, which makes the spikes easier to leave. Every two petals, a checkpoint remains.

That gray stretch mixes guns, flower-headed horses, spikes made of corpses, flytraps, a bomb that fires a cross or an X, waving hands, and a face that follows you.

• Patchworked: shoot the two bouncing flowers beside him. Buttons fall, and finger-guns fire rusty nails. The hands themselves do not hurt.
• Organic: shoot the red blood cell on the heart, then the heart. The loose red cells pop in one shot. A purple virus dashes at where you are standing.
• Clay: vines grow clay thorns. Shoot the red one while it moves. Clay piles into an eyeball that sweeps a blue beam from the left or an orange beam from the right.
• Paper: paper petals travel up to the top. Destroy one red petal on each side. Wads and paper airplanes cross the screen.
• Polygonal: the bottom two petals go first, then the whole body turns red. Spikes cross the screen. A stickbug crawls down and dies after eight shots. The vines drawn at the sides do not hurt.
• Mechanical: two fist drones hover beside him. Destroy both. He fires from his face, and a drone that is still up fires eight bullets. After a warning, sawblades come in from the sides.

After the sixth petal, the attacks ease off and then slow until they stop. You still have to live through that last stretch. When it ends, the battle is over.

The phase before the petals

Before Meta Flowey, the Neutral fight is still Flowey, and Check calls him your best friend. He throws five friendliness pellets once, the same opening as his tutorial, and that is the only time he uses them. He reloads his SAVE so FIGHT, items, and the negatively named ACTs do nothing. Progress is three mazes: reach the SAVE at the end while vines poke in. A maze can look like the Ruins, the Dark Ruins, Waterfall, the Dunes, the Steamworks, or Hotland, and the overworld sprite in there is pure yellow. A cleared maze is a checkpoint. Whatever your LV, that battle sets your max HP to 100. Best Friends Forever plays under this phase.

The fight in the frame is the petal phase. The Dark Ruins portion is still unfinished in a separate Scratch project, UNDERTALE YELLOW - Flowey Fight by jforthewin12. That author is leaving phase 2 to RatchetJobaria. The keys there are different: Z prays, X screams, and the arrows run.

Other fights

Undertale's six-SOUL boss is a different fight. Omega Flowey fight simulator is the Neutral Route battle after Asgore. Undertale does not print the name Omega Flowey either.

The other Undertale battle on this site is the Sans fight simulator in the judgment hall.

A yellow SOUL also shoots in the Spamton NEO fight simulator where holding Z charges a heavy round. This Meta Flowey project uses Z to interact and X to dash.

Open the Black Knife simulator for the Roaring Knight's sword.

Open the Jevil fight simulator for the Chapter 1 secret boss.

Another copy of this petal fight is on Deltarune Fight as well.

How to dodge

In the real Neutral fight, phase 1 forces you to 100 HP and 0 defense. Every attack in that phase deals 12. FIGHT, items, and the negatively named ACTs get reloaded away. Each of the three sections opens with three attacks drawn from a pool: pellet rings, a mouth arc with one gap, cartoon copies that swap you with a white soul, shattering white souls, petal streams, thorn lines, homing rings, a head spraying pellets and spikeballs, and splitting tears.

After those, you get distorted, faster versions of bosses you killed. Spared bosses are skipped. Then white hands fill the screen. Touching them drains HP fast. The first section's hands can be mostly dodged by standing still. Then a maze: reach the SAVE point while vines poke in. Clear it three times. Each clear is a checkpoint. Endure, Hope, and Persist heal 30. Each has about a 20% chance to show up, and about half of turns offer at least one.

Phase 2 is the petal fight in the frame. The box is the lower half of the screen. The heart is yellow, so it shoots, and X dashes in this project. Gray attacks run for about 25 seconds: guns, flower-headed horses, corpse spikes, flytrap fire, a bomb that throws a cross or an X, waving hands, and a face circled by spikeballs that follows you. Shoot one of six petals to enter it. Shoot the red weak points. Clearing a petal heals 60. In the real fight the dash unlocks after the first petal and stays for the rest of the battle, which makes the spikes easier to leave. A checkpoint remains every two petals. After all six, live until the attacks slow to a stop.

• Patchworked: two bouncing flowers. Buttons fall. Finger-guns fire nails. The hands themselves do not hurt.
• Organic: shoot the big red cell, then the heart. Loose blood cells pop in one shot. A virus dashes at where you are standing.
• Clay: the red thorn moves. After about nine seconds an eyeball sweeps a beam. Eyeballs and clay fall.
• Paper: one red petal on each side. Wads and paper planes cross the screen.
• Polygonal: the two bottom petals, then the whole body. Blue spikes cross. Red spikes burst into pellets. A stickbug takes eight shots.
• Mechanical: two fist drones. He fires from his face, drones burst, and sawblades come from the sides after a warning.