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FNF vs Sans Rhythm Battle

Developer: Grid Reapers

Published: 2025-06-14

Updated: 2026-06-12

Reviews

FNF vs Sans (Fallen Star) offers a polished rhythm game experience. The original songs are well-made and fit the Undertale theme. Controls are responsive and the difficulty curve is fair. The web version runs smoothly on various devices, making it accessible. Replay value comes from trying higher difficulties and perfecting your timing. It is a solid fan mod that respects both source games.

Description

Game Introduction

FNF vs Sans (Fallen Star) is a rhythm game mod based on Friday Night Funkin. In this musical showdown, you control Boyfriend as he sings against Sans from Undertale. The mod includes original songs and a visual style inspired by the Undertale universe. This web-optimized version works on many devices, including older computers, Chromebooks, and Linux systems. The game is free to play and encourages support for the original creators.

How to Play

Use the arrow keys on your keyboard to match the on-screen prompts. Press the correct arrow key in time with the music to score points and keep the rhythm. The game offers multiple difficulty levels for beginners and experienced players. Songs become faster and more complex as you progress. Your goal is to outlast Sans in each battle and complete all songs to win. If you miss a note, simply keep trying.

Game Features

Family-friendly rhythm battles with catchy music. Simple arrow key controls for easy learning. Multiple difficulty levels to match your skill. Smooth performance on older devices and Chromebooks. Free to play with no downloads required. Original songs inspired by Undertale.

Tips for Success

Practice each song on an easier difficulty before attempting harder levels. Focus on maintaining a steady rhythm rather than speed. Pay attention to the visual cues on screen to anticipate upcoming notes. Take short breaks if you find yourself missing many notes, as fatigue can affect timing. Consistent practice will help you master the patterns and improve your score.

Compatibility

▸ Desktop: Chrome / Edge / Firefox / Safari

▸ Mobile: iOS Safari / Android Chrome

▸ Tablet: iPadOS Safari / Android Tablet Browser

Keep your browser updated for the best experience

Faq

Is FNF vs Sans (Fallen Star) suitable for children?

Yes, this game is family-friendly and does not contain violent or inappropriate content. It features musical battles with cartoon characters, making it suitable for players of all ages.

Do I need to download anything to play this game?

No, this is a web-optimized version that runs directly in your browser. No downloads or installations are required, and it works on many devices including Chromebooks and older computers.

Can I play this game on a mobile device?

The game is optimized for keyboard controls, so it is best played on a device with a physical keyboard. Touchscreen support may vary, but it is primarily designed for desktop and laptop use.

Are there multiple songs in this mod?

Yes, the mod includes several original songs inspired by the Undertale universe. Each song presents a unique rhythm challenge, and they become faster and more complex as you progress through the game.

What happens if I miss a note during a song?

If you miss a note, you can simply continue playing. The game does not end immediately; you can keep trying to complete the song. Missing notes will affect your score, but you can always restart or try again.

Is this game officially affiliated with Undertale or Friday Night Funkin?

This is a fan-made mod that combines elements from both games. It is not officially affiliated with the creators of Undertale or Friday Night Funkin. The developers encourage supporting the original creators.