A short Deltarune roguelike with SOUL upgrades and Jevil.
Take Kris, Susie, and hatless Ralsei through two shuffled encounters, visit Rouxls’s shop for free upgrades, then face Jevil. Keep Deltarune’s turn-based menus and green battle box while speed, shield, and dash upgrades change how you dodge. Health carries through the run. Play solo using your Windows Steam copy of Deltarune, including Chapter 5 for the party sprites. Inspired by Isaac; only Deltarune is required.
Fight Rudinn and Rabbick in shuffled order, choose an upgrade after each encounter, then face Jevil. Native FIGHT, ACT/MAGIC, ITEM, SPARE and DEFEND, TP and attack timing are all part of combat. Jevil can be defeated through attacks or mercy: four Hypnosis ACTs make him tired and spareable, and Pacify works too.
Start with three Dark Candies. Current health carries between encounters with no automatic room-clear healing. Downed heroes receive Deltarune's small victory revival; items and spells can still heal. Defeat offers a retry and victory offers a fresh run. Upgrades reset on a fresh run. Normal story saves are not written.
Choose one free upgrade per visit. Swift Thread makes your SOUL faster, Orbit Charm blocks hostile bullets, and Blink Thread uses your configured Menu button to dash through bullets. An upgrade you already own becomes Party Recovery, restoring 40% of each hero's maximum HP. Browse with arrows and confirm your choice.
Each run shuffles Rude Buster, Vapor Buster, Ruder Buster and Rakuichi Buster, giving the two regular encounters different tracks. Rouxls's shop plays Hip Shop; Jevil plays The World Revolving. Music is read from your installed game.
The shop has native Rouxls art and music, original pixel icons and Rouxls-style descriptions. Encounter scenery matches the enemies; the party's animations, portraits and final victory poses use Chapter 5 sprites, including hatless Ralsei.
Solo and offline. Requires Windows Steam Deltarune with Chapter 1 and Chapter 5 installed: executable 1.0.0.2, Chapter 1 data 1.43 and the matching Chapter 5 build. Both chapter files are checked before launch; other builds receive a compatibility message.
This is a native Chapter 1 mod running in your actual Deltarune executable from a private game copy. Melty passes your installed game's folder, and the launcher prepares the patch and Chapter 5 sprites automatically. All required tools are bundled. The first launch includes preparation; later launches reuse the cache. Steam's files remain intact. Isaac is inspiration only and is not required.
Use your configured Deltarune controls. Defaults: arrows; Z/Enter to confirm; X/Shift to cancel or slow; C/Ctrl for Menu/Blink. F11 toggles fullscreen; Escape quits.
Deltarune: Toby Fox and team. Music: Toby Fox; Rakuichi Buster arrangement by Rakuichi. The Binding of Isaac: Rebirth: gameplay inspiration. DeltaIsaac's original code, procedural scenery and icons were made with Codex assistance.
Original mod code and icons are MIT licensed, and remixes are welcome. Game assets retain their owners' permissions and are read from your own copy. Bundled tools retain their own licenses; matching UndertaleModTool/Underanalyzer source and complete notices are included.
Tool credits: UndertaleModTool and Underanalyzer contributors; xdelta3 by Joshua MacDonald; Python Software Foundation; Pillow and PyInstaller contributors; Microsoft .NET/Roslyn/System.CommandLine contributors; Magick.NET by Dirk Lemstra; Newtonsoft.Json by James Newton-King; SharpZipLib contributors. See the bundled THIRD_PARTY_NOTICES.md for licenses and source links.
