The most prominent project is , a homebrew port created by a developer named Cervi . This version is not a standard ROM that you can simply download and play; it requires a "legitimate" copy of the game to work, as the developer aims to prevent piracy.

: As of 2026, the project is still considered a "Work in Progress" or prototype. While early demos featured the intro and first 15 minutes of gameplay, updates have continued to expand the project's scope. How to Legally Access the "Undertale DS ROM"

If you're interested in playing Undertale but don't want to download a ROM, consider these alternatives:

Leo’s heart gave a little flutter of excitement. "Okay," he whispered. "Show me what you got."

, developed by the creator Cervi. This isn't a simple ROM you can just download and play; it's a technical feat that requires users to provide their own legal copy of the game. How the Homebrew Port Works

: Visit official development pages like Cervy's GitHub or CooingMaxito's GitHub .

To run these on actual hardware like a DS Lite or 3DS, you typically need a homebrewed console or a flashcart (e.g., R4 card).

C3RV1/UndertaleNDS: Undertale port for Nintendo ... - GitHub