(often abbreviated as BnP) is a massive, fan-made "remaster" mod for Toby Fox's Undertale . It is designed to overhaul the entire game, from its visual aesthetic and music to adding entirely new gameplay mechanics and locations. Key Features & Gameplay
Explorers can find entirely new areas, such as the Sewers , that weren't in the original game.
Every room, character sprite, and battle background is redesigned with higher detail. The soundtrack features remixed versions of the original scores.
It incorporates mechanics from Deltarune , such as the ability to run using sneakers.
Players can encounter new monsters, secret boss fights, and various cameos or Easter eggs from other fan projects. Installation Guide
It backports console-exclusive content—like the Mad Mew Mew fight—to the PC version.
The mod transforms the original experience by adding modern polish and new content, including:
Guide :: How to Install Undertale Bits and Pieces - Steam Community