Undertale 10th Anniversary

Experience Undertale 10th Anniversary UT10 Battle through bullet-hell combat and smart ACT choices. Master patterns, dodge attacks, and shape your ending.

About Undertale 10th Anniversary

To celebrate the 10th anniversary of Undertale, the gaming community got to experience UT10 Battle, a browser-based combat mini-game that recreates the signature gameplay that made the original game famous.

Pacifist Sans Battle: Rhythm-Based and Reflex-Based Gameplay

The central character of the first battle is Sans, one of Undertale's most iconic bosses.

Attack Mechanism

• Attack primarily uses bones that fly horizontally, vertically, and spin around.
• There are no Gaster Blasters or KARMA effects like in the Genocide battle in the original game.
• Some SOUL-pushing mechanics create a slight sense of loss of control, requiring players to adapt quickly.

Gameplay Focus

This match doesn't focus on extreme difficulty but rather on:

• Pattern reading ability (bullet patterns)
• Rhythmic reflexes
• Safe zone identification

Notably, choosing FIGHT will result in almost immediate punishment, a design element that emphasises Undertale's familiar pacifist philosophy.

Mr.Sunshine and Aberrant: Tactical Bullet Hell

The second match introduces two new characters, with Mr.Sunshine being the most prominent. Unlike Sans, this match emphasises:

Coordinated attacks targeting two targets

• Two enemies can attack simultaneously.
• Multi-layered bullet patterns (multi-directional, diagonal, rotating).
• Cornering maneuvers that require pixel-perfect precision.

ACTs directly impact gameplay

ACT choices are not just dialogue but also:

• Slow down the attack speed
• Change attack patterns
• Unlock different endings

This makes gameplay more than just dodging; it's a strategic interaction.

Control System

• Arrow keys: Move SOUL (red heart)
• Z: Confirm
• X: Back

The combat interface retains the classic structure: FIGHT - ACT - ITEM - MERCY

SOUL Design: Control-Centric Feel

Like in Undertale, SOUL is the core of gameplay:

• No stamina bar.
• No complex combos.
• Just you, the red heart, and limited space.

This minimalism creates:

• High tension.
• Complete focus on individual skill.
• Every mistake is valuable.