I booted up Undertale again in the spring of 2026, and the Underground felt less like a cave and more like a broadcast tower built inside a migraine. Mettaton was waiting. He is a robot without a SOUL, assembled by Dr. Alphys as an entertainment machine, but somewhere along the way he became a human killer and a star with a television show monsters actually watched. He has three forms; two of which I met in every route. By the time I reached his lair, I had already blundered through his quiz show, cooking show, news segment, and musical play. I did not feel like a hero. I felt like a stagehand who had accidentally walked onto the set of a live execution.

🎬 The Curtain Rises in Hotlands

My first meeting with Mettaton was not a duel. It was a quiz show inside Alphys' lab, then a cooking show, then a news segment, and finally a musical play. Each encounter was a little mousetrap dressed as a broadcast. When I finally cornered him in the lair, I fought the boxy Mettaton for only a few turns before Alphys shouted from the sideline and told me to flip the switch on his back. The moment I did, Mettaton EX burst out like a firework with a PR budget.

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💛 The Ratings War

The fight was not the hardest I have faced, but it was a disco marathon where the floor kept changing rules. I was locked in the Yellow Soul phase the entire time. Every hit he landed chewed 6-7 HP, which would not sound like much until three hits landed in one turn and my inventory of healing items started sweating.

His legs moved side to side like two tuning forks dipped in malice. I had to strike each leg once, then weave into the empty space before the next pass. Then small Mettatons fell from the ceiling like chrome confetti from a birthday hosted by a slot machine. I shot them before they could throw hearts at me.

After enough turns, Mettaton EX pushed his own heart out like a showman offering an encore and began lobbing projectiles from it. The target was the heart itself. Every clean hit removed a limb, and I could feel the fight losing its shape.

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At the top of my vision, the ratings ticked upward like a lie detector connected to my panic. Taking damage raised the number. Eating food from a popular brand raised it further. I had to check the ratings constantly. The battle would end when the ratings reached 10,000, but only if Mettaton had lost all his limbs. If I let the numbers climb while he still had a single chrome finger attached, the fight would drag to 12,000. That was the likely outcome on both the Neutral and True Pacifist routes.

💀 The Unplayed Piano Key

On the Neutral Route, there was a darker option: actually kill Mettaton EX. The method sat in my mind like an unplayed piano key I had no business touching. To do it, I would need to keep the ratings below 10,000, not above. Only junk food would lower them. Waiting between turns would lower them slowly. During the essay writing segment, typing a curse word would drag the numbers down like a censor's eraser. It was not advised, because Mettaton dies, and it made the fight harder. I tried it once out of curiosity and felt the kind of quiet you only get after smashing a stage prop someone loved.

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⚡ Mettaton NEO and the Genocide Route

On the Genocide Route, after I had hollowed out most of the Core, Mettaton appeared in a different form: Mettaton NEO. He spoke about protecting the people he cared about, much like Undyne the Undying. It should have been a grand fight. Instead, my first attack erased his health bar like a match blown out by a passing train. He was too weak to take the blow. Chara finished him.

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Route	Form	How It Ends
Neutral / True Pacifist	Mettaton EX	Ratings reach 10,000 after limbs are removed, or 12,000 if any limb remains
Neutral alternate kill	Mettaton EX	Keep ratings below 10,000 with junk food, waiting, and curse words, then destroy him
Genocide	Mettaton NEO	First attack deletes his HP bar

Mettaton remains one of the strangest bosses I have ever fought. He is a hollow star with no SOUL, but his ratings mattered more to me than my own HP. In 2026, that still feels a little too real.