I still remember the first time I booted up Undertale on a hand-me-down PC. A friend had told me it was a quirky RPG, but that did not prepare me for Flowey's unsettling welcome or Toriel's gentle guidance through the Ruins. Within an hour, I realized something strange: I cared more about talking to monsters than fighting them. That feeling has never left me.

Undertale launched in 2015 and turned the indie scene upside down. Built in GameMaker Studio, it cast me as a fallen child exploring the Underground, a secret realm beneath the earth protected by a magical barrier. It called itself 'the friendly RPG where nobody has to die,' and somehow that promise did not feel like a gimmick. Rather than forcing me to slash every monster, the game gave me a menu: FIGHT, ACT, ITEM, and MERCY. I could study a monster's body language, tell a joke, flirt, or simply refuse to hurt them. The bullet-hell defense sections turned every hostile encounter into a conversation, and I often held my breath while dodging magical attacks, hoping my mercy would land.

Why This Game Took Over My Life

What made Undertale special was not just its clever systems. It was the writing. Sans and Papyrus delivered skeleton puns that made me laugh out loud. Undyne, Mettaton, and Asgore carried real emotional weight, and the fourth-wall-breaking boss fights made me feel as though the game was personally watching me. Every area had music that I could not stop humming, especially the now legendary Megalovania.

Critics and fans agreed. The pixel art, the emotional storytelling, and the pacifist philosophy earned Undertale multiple Game of the Year nominations and more than a million copies sold. But behind all that success was a quiet creator named Toby Fox.

The Creator Behind the Underground

Toby Fox was born in 1991 and first made a name for himself composing music for Homestuck. He had also experimented with game creation using RPG Maker 2000, famously producing the Earthbound Halloween Hack. When he made Undertale, Fox handled the dialogue, design, and music, while Temmie Chang contributed the game's distinctive artwork. That handmade quality comes through in every screen. It feels like a strange, heartfelt letter to classic RPGs like Earthbound, but with its own wicked sense of humor.

Deltarune: An Anagram and a New Mystery

I learned later that Deltarune actually began development before Undertale, all the way back in 2012. The title is an anagram of Undertale, but the world is not simply a retread. In Deltarune Chapter 1 and Chapter 2, I became Kris, a teenage human in a town that feels ordinary until I fell into the Dark World. There I met Susie and Ralsei, and combat adopted a party-based flow closer to the fighting mechanics of Final Fantasy. Random encounters were gone, and I had more control over how and when I fought. The central question remained: violence or peace?

Some players have criticized Deltarune for sticking too close to Undertale's formula, and I understand that concern. At the same time, the Dark World's strange logic, the school-drama framing, and the secret Snowgrave route in Chapter 2 gave me chills in a way the original never quite did. Toby Fox plans to release more chapters, but chronic wrist and hand pain has slowed his pace. As of 2026, I am still waiting for the next major drop, and I am fully prepared to replay the first two chapters before it arrives.

Here is a quick comparison that helps me explain the two games to friends:

Element	Undertale	Deltarune
Main character	Frisk, a fallen child	Kris, a teenager
World	The Underground	Hometown and the Dark World
Combat	Bullet-hell defense with ACT and MERCY	Party-based, TP meter, no random encounters
Release	2015	Chapter 1 in 2018, Chapter 2 in 2021

Music That Refused to Stay in the Game

One of my favorite things about Toby Fox's career is how far his music has traveled. After the success of Undertale, Fox contributed to the soundtracks of major games like Pokémon Sword and Shield and Super Smash Bros. Tracks such as Megalovania inspired countless covers, remixes, and memes. I have lost count of how many times a random video used that song, and every time it pulls me back to the moment I faced Sans for the first time. It is a strange joy to hear a beloved indie melody woven into a massive crossover.

What Keeps Me Playing in 2026

A decade later, Undertale still feels urgent. It asks whether mercy can be a viable strategy, not just in a game but in how we treat people. It also asks questions about determination, memory, and consequences. Why do I keep returning to the Underground? Because every playthrough reveals a new line of dialogue, a new detail, or a new reason to care. The game may look old-school, but its heart is timeless.

As for the future, Toby Fox has not announced much beyond the rest of Deltarune. But if his past work is any guide, the next chapter will be strange, funny, and surprisingly moving. I will be there, controller in hand and heart wide open, ready to spare as many monsters as I can.