Dustswap Dusttrust Fight Simulator

How to Play Dustswap: Dusttrust (Phase 1-3)

Dustswap Dusttrust Fight Simulator is an exhilarating Undertale alternate universe boss battle created by developer Modeck. Combining the psychological madness of Dusttale with the inverted roles of Underswap and the apocalyptic escalation of Dusttrust, this project pits you against a deranged, dust-covered Sans driven to horrific extremes across three relentless combat phases. Scored in Phase 1 by the furious track Homicidal Lunacy (composed by benyic03), this battle demands razor-sharp reflexes and meticulous spatial control.

To begin the duel, click directly inside the game window so your browser registers directional keyboard inputs without delay. The battle begins in Phase 1, where Sans unleashes high-density bone clusters, sudden platform shifts, and disorienting soul manipulations. Control your SOUL using the Arrow Keys to weave through tight corridors of bone skewers and avoid devastating energy waves. Confirm menu selections with Z and back out of choices with X.

This simulator features advanced combat and progression controls that set it apart from standard encounters:

• Emergency Healing with Spacebar: Surviving the high-density bone hazards can quickly deplete your health bar. By pressing the Spacebar, you instantly restore your HP to maximum, providing a built-in training tool to master difficult attack patterns without enduring repeated Game Over screens.
• Phase Transitions with 0 Key: Unlike linear versions where reaching subsequent phases requires completing an entire grueling battle sequence, you can seamlessly jump between phases. Pressing 0 (Zero) immediately transitions the encounter from Phase 1 into the chaotic showdown of Phase 2. While in Phase 2, pressing 0 once more advances the battlefield into the cataclysmic climax of Phase 3.
• Slashing Mechanic in Phase 2 (R Key): Once you enter Phase 2, the duel evolves beyond passive evasion. Pressing R unleashes a sweeping slash attack, allowing you to strike back against Sans and breach his mystical bone wards during active combat segments.
• Interactive Battle Triggers: Designed with extensive player exploration in mind, the game provides comprehensive debug and attack testing keys. Pressing Q terminates the active enemy turn, while numeric keys (4, 5, 7, 8), letter keys (C, B, N, F, H, J, K), and upper-row inputs (T, Y, I, O, P, U, L) allow you to trigger specific bone mechanics, soul shifts, and special bullet sequences on demand.

Controls, Phase Keys, and Attack Triggers

Use the numeric 0 key to transition between phases, and tap Space whenever you need to restore your health during challenging bone barrages.

About Dustswap: Dusttrust and Modeck's Version

Dustswap: Dusttrust occupies a unique intersection within the Undertale AU community. Built upon the robust battle engine created by nikarosi, featuring a custom bone collision engine developed by Modeck, and brought to life with detailed custom Sans sprites created by bluebonestudios, this version synthesizes three separate fan concepts into a unified narrative epic.

To understand the background of this battle, it is helpful to examine the lore lineage that inspired its creation:

• The AU Genealogy: Dusttale explored a timeline where Sans absorbed monster souls through genocide to gain sufficient LOVE to defeat the anomaly. Underswap reversed character personalities and roles, placing Sans in Papyrus's role as the ambitious sentry. Dusttrust further adapted this premise into a high-stakes tragedy where Sans wields emerald magical blades and blasters. In Modeck's Dustswap: Dusttrust, the intense role-swap dynamic is paired with escalating multi-phase bullet hell choreography.
• Three Distinct Battle Phases: Phase 1 features the pulse-pounding theme Homicidal Lunacy, challenging players with fast-moving bone crossfires and rapid gravity shifts. Phase 2 introduces armed blade-combat and custom slash inputs (via the R key), reflecting Sans's desperate struggle as his sanity fractures. Phase 3 unleashes overwhelming screen-filling barrages representing the full destructive power of a monster consumed by genocide.
• Custom Engine Architecture: Rather than relying on rigid, pre-rendered attack cycles, Modeck's bone engine calculates dynamic projectile trajectories, smooth collision boxes, and responsive soul physics. This architecture enables player-controlled attack summoning and phase skipping, making it both a grueling challenge and a comprehensive sandbox for AU enthusiasts.

If you enjoy testing your endurance against legendary AU encounters like Dusttrust Sans Fight or exploring the emerald climax of Dusttrust Finality, Modeck's three-phase simulator offers an indispensable chapter in Undertale fangame history.

Encounter Progression and Phase Mechanics

Dustswap: Dusttrust provides a structured multi-phase journey with distinct mechanical identities for each stage of the duel:

• Phase 1 — Homicidal Lunacy: The battle opens with classic Undertale combat mechanics pushed to extreme tempos. Sans hurls dense bone fields, rapid vertical skewers, and alternating blue/white bone gates across the arena. Success requires mastering short, rhythmic hops under blue gravity and positioning your soul in safe central gaps.
• Phase 2 — The Armed Confrontation: After pressing 0 or enduring Phase 1's full onslaught, Sans takes up direct melee weaponry alongside his magic. In this phase, dodging alone is insufficient: players must press R to execute slash counters that deflect oncoming strikes and crack through his defensive barriers.
• Phase 3 — The Cataclysmic Finality: Triggered by pressing 0 while in Phase 2, the final phase strips away all restraint. The arena expands, bullet densities reach apex saturation, and Gaster Blasters fire continuous beam crossfires. Only flawless reaction timing or strategic use of the Space healing tool will allow you to survive this apocalyptic climax.

Combat Strategy and Evasion Techniques

Conquering Sans's relentless barrage across all three phases requires disciplined positioning and smart key usage:

1. Master Low Hops on Blue Gravity Bones: When Sans slams your soul into blue gravity, tapping the Up Arrow gently produces a micro-hop just high enough to clear incoming floor bones. Holding the key causes your heart to vault into high-flying ceiling hazards.
2. Prepare the R Key for Phase 2 Counters: Keep your left hand on the R key as soon as you transition into Phase 2. Timing your slash strikes the instant Sans closes the distance will prevent him from trapping your soul against the arena walls.
3. Utilize Phase Skipping for Focused Practice: Don't waste energy replaying Phase 1 if your goal is mastering the complex slash mechanics of Phase 2 or the intense projectile storms of Phase 3. Press 0 to jump directly to your desired phase and practice individual patterns.
4. Observe Bone Skewer Audio Cues: Before vertical bone walls erupt from the floor or ceiling, the game plays distinct warning sounds. Immediately shift horizontally away from the sparkling floor indicators to avoid taking instantaneous contact damage.
5. Use Q to Reset Stagnant Turns: If you trigger a debug attack pattern or become pinned in an impossible corner during practice, pressing Q safely ends the turn, returning you to the command menu without requiring a full game reload.
6. Leverage the Spacebar Heal Wisely: Pressing Space instantly refills your health. While attempting a pure no-hit run is the ultimate challenge, using Space during your initial playthrough allows you to learn the rhythm of Phase 3's final patterns without frustration.