Cliffside Sacrifice

A Playdate Arcade-Puzzle Game Theme: Pay to Win (interpreted as Sacrifice) Platform: Playdate (Lua) GDD Version: 1.0

---

1. High-Level Concept

Cliffside Sacrifice is a physics-inspired arcade puzzle game where the player controls a team of tethered climbers attempting to ascend a cliff by swinging, launching, and catching new pivot points. Progress requires careful timing, mastery of pendulum motion, and strategic sacrifice of climbers to reach difficult pivots.

The game interprets the jam theme "Pay to Win" as paying with sacrifice—discarding parts of your team to overcome otherwise impossible obstacles. Levels are tall vertical cliffs. The climbers start near the top and must swing and launch their way downward, moving with gravity to reach goal pivots near the bottom of the level.

---

2. Core Gameplay Loop

1. Player begins a level with a rope composed of multiple segments, each ending with a climber.
2. The top climber is attached to a pivot point.
3. Player uses the D-pad or crank to actively pump the pendulum at the right moments to build momentum.
4. Pressing A:
   • Attempts to grab a pivot if within reach.
   • Or, if timed during a backswing, releases to sling the bottom climber toward a distant pivot.
5. If the climber reaches a new pivot and A is pressed at the right time, the rope reattaches, shifting the pivot upward.
6. Player continues decending pivot by pivot until reaching a finish pivot.
7. Player may press B to sacrifice the lowest climber, shortening the rope for stronger swings.
8. Level ends when reaching a finish pivot with ≥2 climbers.

---

3. Player Controls

Movement & Pendulum Pumping

• D-pad Left/Right or Crank Used to pump the swing. Timing matters: pumping at the apex or trough increases angular velocity.

Actions

• A Button

  • Press near a pivot → attempt to grab it.
  • Press at the right time during an upward swing → sling the end climber for distance.
  • No auto-grab—manual grabbing only.

• B Button

  • Sacrifice (release) the lowest climber, shortening the rope by one segment.
  • Only allowed when the top climber is attached to a pivot.

Other

• Menu button → Pause/settings
• Player can choose D-pad or crank control style.

---

4. Physics & Movement

Pendulum Simulation

• Simplified pendulum math (not full Box2D).
• Only the end climber has mass and determines swing motion.
• Intermediate climbers have no physical effect while the rope is anchored.

Swing Mechanics

• Angular velocity increases when the player pumps effectively (timed inputs).

• Rope length affects swing frequency:

  • Longer = slower, wider arc
  • Shorter = faster, tighter swing

Launching

• Releasing A on an upswing uses the current velocity vector to project the climber.
• If the climber trajectory enters a pivot’s grab radius, pressing A again catches the pivot.

Failure to Grab

• Missing a pivot simply continues the trajectory.
• No auto-grab.

---

5. Climbers & Rope

Climbers

• Start with 2–5 climbers depending on level config.
• Represented initially with simple shapes; future stretch goal includes pixel art.
• Climbers correspond to rope segments.

Rope

• Rope consists of multiple segments, each ending in a climber.
• Length determined by the sum of segment lengths defined in level JSON.
• Rope reattaches instantly when grabbing a pivot.
• Rope shortens when sacrificing the bottom-most climber.

Sacrifice

• Pressing B removes the lowest segment + climber.
• Can be done while swinging, as long as the top climber is attached.
• Instantly affects physics (rope becomes shorter).

---

6. Sacrifice Mechanics (“Pay to Win”)

The core thematic mechanic.

Triggers

• Pressing B → intentional sacrifice.
• Missing a pivot → potential accidental loss (falling off-screen).
• Wobbly pivot breaking → all climbers fall (instant fail).

Rules

• Must finish with ≥2 climbers.

• Losing all climbers = instantaneous level failure.

• Sacrificing allows:

  • Stronger swings (shorter rope).
  • Tighter control.
  • Higher precision launches.

Risk/Reward

• More climbers = more reach but less control.
• Fewer climbers = easier swinging but higher chance of total failure.

---

7. Pivots & Level Objects

Pivot Types

1. Stable

   • Permanent anchor point.
   • Never breaks.

2. Wobbly

   • Breaks under conditions:

     • After time-to-break OR
     • After swing-count-to-break

   • Once broken, all climbers fall.

Finish Pivots

• Represent level completion.
• Marked in JSON as isFinish: true.
• Levels may contain multiple finish pivots.

---

8. Levels & Progression

Structure

• Levels are vertically oriented and defined in world space.
• Players start near the top of the level and progress downward toward one or more finish pivots near the bottom.
• Movement direction is primarily down, leveraging gravity to make swinging and launching more expressive and controllable.
• The level has explicit dimensions:
  • evelWidth
  • levelHeight
• World coordinate system:
  • (0,0) is the top center of the level.
  • X increases to the right, X decreases to the left.
  • Y increases downward.

Camera & View

• The camera viewport is the Playdate screen (400 × 240 px).
• Camera is defined in world-space coordinates:
  • cameraX, cameraY represent the top-center of the viewport in world coordinates (same origin as level).
  • The camera always tries to keep all climbers visible, but prioritizes tracking the current pivot (detailed in the Camera section).

Progression

• Early levels introduce:

  • Basic swinging
  • Basic grabs
  • Stable pivots

• Later levels introduce:

  • Wobbly pivots
  • Longer distances requiring launch mechanics
  • Precision timing challenges
  • Sacrifice puzzles

Reset Rules

• Climbers, rope segments, and lengths reset each level.
• No persistent damage or level-to-level carryover.

Failure Conditions

• All climbers lost.
• Reaching a finish pivot with <2 climbers.

---

9. Scoring

Primary Score

• Earn points for completing a level.

• Bonus points awarded based on:

  • Number of climbers remaining
  • Number of sacrifices avoided
  • Time to completion (optional, TBD)

Potential Additional Bonuses (Future)

• Stylish long-distance grabs
• Consecutive successful grabs without falling
• Swing efficiency metrics

---

10. Art & Audio Style

Art

• Minimalist, slightly dark humor tone.
• Early versions use geometric primitives.
• Stretch goal: pixel-art climbers, pivots, rope, backgrounds.

Audio

• Simple swing sounds, release chime, pivot snap, fall scream (if time permits).
• Minimalist background ambience.

---

11. Playdate Constraints

• Black & white, 1-bit display.

• Must support either crank or D-pad for identical mechanics.

• Optimized for performance:

  • Simplified pendulum math
  • Single-body physics (only bottom climber)
  • Efficient rendering with primitives

---

11. Camera & Level Orientation

11.1 World & Camera Coordinate System

• World origin: (0,0) is the top-center of the entire level.

• X-axis:

  • Positive X → right
  • Negative X → left

• Y-axis:

  • Positive Y → downward

• Camera origin:

  • cameraX, cameraY represent the top-center of the viewport in the same coordinate system.

  • The visible screen spans:

    • Horizontally: cameraX - 200 to cameraX + 200
    • Vertically: cameraY to cameraY + 240

11.2 Camera Target: Pivot-Focused Framing

• The current pivot peg is the primary camera target.

• Desired framing:

  • On-screen X ≈ 200 (center of the 400 px screen)
  • On-screen Y ≈ 20 px from the top (pivot appears slightly below the top edge).

• In world-space terms, the ideal camera position is:

  • targetCameraX = pivotX
  • targetCameraY = pivotY - 20
  • (since cameraY is the top of the viewport, placing pivot 20 px down from top).

11.3 Camera Movement (Lerped Tracking)

• The camera does not snap instantly to the ideal position.
• Instead, each frame it smoothly lerps toward targetCameraX, targetCameraY, creating a soft, cinematic follow effect.
• This smoothing avoids jitter when the pivot moves slightly or when the rope swings near a pivot.

11.4 Clamping to Level Bounds

The camera must never show outside the level bounds.

Given:

• levelWidth, levelHeight
• Camera half-width = 200 px
• Camera height = 240 px

Clamping rules:

• Horizontal clamp

  • Camera’s visible area must remain within [ -levelWidth/2, +levelWidth/2 ] (if you treat 0 as center).

  • So cameraX is clamped such that:

    • Left edge ≥ level left boundary
    • Right edge ≤ level right boundary

• Vertical clamp

  • cameraY (top of viewport) is clamped so:

    • cameraY ≥ 0 (can’t go above the top of level)
    • cameraY + 240 ≤ levelHeight (can’t show below the bottom of level)

• If the pivot is near the top or bottom of the level, the camera may stop moving even if the pivot would ideally be at (200,20) to avoid showing outside the level.

11.5 Ensuring Climbers Are Visible

• The camera framing is pivot-centric, but where possible, it should keep all climbers within the viewport.

• Priority:

  1. Keep the current pivot at the desired approximate screen location.
  2. Keep all climbers on-screen; if necessary, the camera may slightly relax the ideal pivot offset to avoid cutting off climbers at the edges (this can be a future refinement / stretch).

---

🧾 12. Data Format (JSON Spec) – Updated with Dimensions

Update the sample JSON spec like this:

{
  "levelName": "Level 1",
  "background": "assets/bg1.png",

  "levelWidth": 400,
  "levelHeight": 1200,

  "segments": [20, 20, 30],

  "pivots": [
    { "x": 0,   "y": 40,  "type": "stable" },
    { "x": 60,  "y": 200, "type": "wobbly", "timeToBreak": 3000, "swingLimit": 5 },
    { "x": -40, "y": 1000, "type": "stable", "isFinish": true }
  ]
}

New Field Definitions

• levelWidth

  • Horizontal span of the level in pixels.
  • Centered around x=0 (top center), so the logical horizontal range is roughly [-levelWidth/2, +levelWidth/2].

• levelHeight

  • Vertical size of the level in pixels.
  • Starts at y=0 (top) and extends to y=levelHeight (bottom).

The previous field definitions for segments and pivots stay the same, just now explicitly live inside these level bounds.

---

13. Future Extensions / Stretch Goals

Art & Content

• Pixel art climbers & animations
• Parallax backgrounds
• Custom rope graphics

Gameplay

• New pivot types (moving, rotating, sliding)
• Environmental hazards (falling rocks, gusts of wind)
• Challenge modes and leaderboards
• Endless “infinite cliff” mode

Meta-Systems

• Story mode with progression
• Unlockable climbers or rope skins
• Speedrun mode