Fun Gang Underground

Kris, Susie and Ralsei fall out of a supply closet and land on a bed of golden flowers.

Play Undertale from start to finish as Kris, with Susie and Ralsei walking behind you. To them, everyone down here looks exactly like somebody from Hometown.

What's in it

• Deltarune's party battles in Undertale's fights. Kris, Susie and Ralsei each choose FIGHT, ACT or MAGIC, ITEM, SPARE or DEFEND. TP builds from hits, defending and grazing; Susie has Rude Buster, Ralsei has Pacify and Heal Prayer. Undertale's own monsters, bullet patterns, ACTs and mercy still decide every fight, bosses included: Toriel, Papyrus, Undyne, Muffet, Mettaton EX and Asgore are all party battles.
• The gang talks. Hundreds of new lines: they cut into Undertale's story scenes, have their own conversations when you look at things and talk to people, and banter in battle. Susie recognises her homeroom teacher. Ralsei keeps looking for a fountain. Kris knows whose house that is.
• Kris is really Kris. Walking, held hands, hugs and umbrellas are drawn from Deltarune's own art, and Susie and Ralsei step aside when someone walks up to him.

How it works

Press Play. The first time, the mashup is put together on your PC from your own Undertale (PC version 1.08) and Deltarune (the full game); that takes well under a minute. Nothing from either game is in the download, nothing is written into their folders, and your Undertale saves are not touched: the mashup keeps its own.

Good to know

• Single player.
• A few scripted showpieces keep Undertale's own battle screen: Mettaton's quiz, essay and bomb segments (he becomes a party battle once he transforms), Undyne's sparring lesson, Monster Kid on the bridge, the Lost Souls, Sans, Asriel and the Flowey finale.
• Three heroes hit harder and last longer than one human, so fights are easier than in plain Undertale.
• The name you type at the start is still the fallen human's. The hero you walk around as is Kris.

Credits and licence

• UNDERTALE and DELTARUNE are by Toby Fox. This is an unofficial fan project, not affiliated with or endorsed by him.
• Built on UndertaleModLib and Underanalyzer by the Underminers team.
• The mashup's own program, design sheets and dialogue are free software under GPL-3.0-or-later; the full source is attached to every release.