platformer

Q: How do I install platformer?

Run npx skills add https://github.com/gamedev-skills/awesome-gamedev-agent-skills --skill platformer in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/platformer/ (personal) or .claude/skills/platformer/ (project).

by gamedev-skillsAI & Agents

Build a 2D platformer: run/jump control with coyote time, jump buffering, and variable jump height, plus tiled levels and hazards. Use for a platformer or Mario/Celeste-like, or tuning jump feel.

Installs: 6.4K
Last 24h: +333
Trending rank: #899
Security: Pass

Install

Works with every agent the skills CLI supports.

npx skills add https://github.com/gamedev-skills/awesome-gamedev-agent-skills --skill platformer

01
Install
Run the command in your project. The CLI asks which agents to install for.
02
Describe the task
Ask your agent for something this skill covers. It loads platformer automatically when relevant.
03
Review the result
The agent follows the SKILL.md steps, scripts and references bundled with the skill.

Security audits

Independent scans of the skill's instructions and bundled files.

Gen Agent Trust Hub PassSAFE ·The skill provides instructional content and pseudocode for developing 2D platformer mechanics. No security risks were identified.

Socket PassNo alerts

Snyk PassLOW ·Risk: LOW · No issues

SKILL.md

The instructions your agent reads when the skill is triggered.

Platformer

A playbook for 2D platformers — the run/jump controller "feel", level structure, hazards, and goals. This is a compositional skill: it wires an engine movement skill, a tilemap skill, and design skills into a working game. It does not re-teach physics or tilemaps; it tells you what to build and how to make jumping feel good.

When to use

Use when building a side-scrolling or single-screen platformer, a "Mario-like" / "Celeste-like", or any game whose core verb is jump between surfaces.
Use when a jump feels floaty, unresponsive, or "unfair" and you need feel fixes (coyote time, jump buffering, variable height, corner correction).

When not to use: top-down movement with no gravity → use the engine movement skill directly. 3D first-person traversal → fps-shooter. Grid/turn movement → roguelike. For the raw kinematic body API, use godot-2d-movement (or your engine's controller skill).

Core loop

Observe a gap/hazard → commit to a jump or move → land safely (or die) → reach the next checkpoint/goal. A platformer lives or dies on the moment-to-moment feel of that single jump, repeated thousands of times. Tighten the controller first; everything else is content.

Must-have systems

Run/jump controller — horizontal accel/decel, gravity, jump, with the feel aids below.
Solid + one-way collision — ground, walls, and "jump-through" platforms.
Level geometry — a tilemap or hand-placed colliders; the playable space.
Hazards + death/respawn — spikes, pits, enemies; reset to the last checkpoint.
Checkpoints / level goal — progress markers and a win condition (flag, door, exit).
Camera — follows the player with a deadzone and look-ahead, clamped to level bounds.
Juice — landing dust, squash/stretch, hit-stop, sound. Cheap, huge feel payoff.

Design knobs (make the jump feel right)

Tune these by outcome (height in tiles, time to apex in seconds), not by raw numbers.

Knob	Effect	Sane starting point
Max jump height	reach	3–4 tiles
Time to apex	"weight"/snappiness	0.30–0.40 s
Fall gravity multiplier	snappy, non-floaty fall	1.5–2.0× rise gravity
Coyote time	jump just after leaving a ledge	0.08–0.12 s (~5–7 frames @60)
Jump buffer	press just before landing still jumps	0.10–0.15 s
Variable jump cut	tap = short hop, hold = full	cut upward velocity ×0.4–0.5 on release
Apex hang	brief float at the top for air control	reduce gravity ×0.5 near `
Ground accel / friction	responsiveness vs. ice	reach top speed in 0.05–0.1 s
Corner correction	nudge past a ledge clipped by 1–2 px	nudge up to ~4 px sideways

Derive gravity and jump velocity from the feel values rather than guessing — see Pattern 1.

Patterns

1. Solve jump physics from height + time (not magic numbers)

# Pseudocode. Pick the FEEL you want, then derive the physics. y-axis points DOWN.
# From kinematics: h = (g * t^2) / 2  and  v0 = g * t.
JUMP_HEIGHT   = 3.5 * TILE      # how high, in world units
TIME_TO_APEX  = 0.35            # seconds to reach the top

gravity       = (2 * JUMP_HEIGHT) / (TIME_TO_APEX ** 2)   # rising gravity
jump_velocity = -(2 * JUMP_HEIGHT) / TIME_TO_APEX         # negative = upward
fall_gravity  = gravity * 1.8   # heavier on the way down → less floaty

2. Coyote time + jump buffer + variable height (the feel core)

# Pseudocode in the per-frame update. dt = seconds since last frame.
# Timers count DOWN; refresh coyote while grounded, buffer on a fresh press.
if on_floor:
    coyote_timer = COYOTE_TIME           # 0.1
if jump_pressed_this_frame:
    buffer_timer = JUMP_BUFFER           # 0.12
coyote_timer -= dt
buffer_timer -= dt

# A jump is allowed if we pressed recently AND were grounded recently.
if buffer_timer > 0 and coyote_timer > 0:
    velocity.y   = jump_velocity
    buffer_timer = 0
    coyote_timer = 0                     # consume both so we can't double-jump

# Variable height: releasing jump early while still rising cuts the arc short.
if jump_released_this_frame and velocity.y < 0:
    velocity.y *= 0.45

# Asymmetric gravity: snappier fall than rise; clamp to a terminal speed.
g = fall_gravity if velocity.y > 0 else gravity
velocity.y = min(velocity.y + g * dt, MAX_FALL_SPEED)

3. One-way platforms

Solid from above, pass-through from below. Use the engine's flag rather than collision math: Godot CollisionShape2D.one_way_collision (or the one-way option on a TileSet collision polygon), Unity a PlatformEffector2D with Use One Way on a collider set to be used by the effector, Phaser Arcade platform.body.checkCollision.down = false (plus left/right for thin ledges). Let the player drop through by ignoring that platform for ~0.1–0.2 s when they hold Down + Jump (refs §5).

Pitfalls / failure modes

Per-frame movement not scaled by dt → speed changes with frame rate. Every velocity integration and timer must use dt. (See physics-tuning.)
Jump height differs between machines → the jump runs on a variable render dt. Simple per-step integration lands a few percent short of the designed height, by a different amount at each frame rate. Run the controller on the fixed physics tick (Godot _physics_process, Unity FixedUpdate) or use the half-step update in refs §1.
Player is flung off or doubles speed leaving a moving platform → platform velocity added twice. Godot's CharacterBody2D already carries the body and adds the platform's velocity on leave (platform_on_leave); don't add it again in script (refs §6).
Floaty jumps → symmetric gravity. Make fall gravity heavier than rise gravity.
"The jump didn't register" → no input buffering. Buffer presses for ~0.1 s before landing.
"I fell off and couldn't jump" → no coyote time. Allow a jump for ~0.1 s after leaving ground.
Sticking to walls / catching on tile seams → use a single capsule/box collider, not per-tile colliders, and add corner correction.
Tunneling through floors at high speed → enable continuous collision / smaller fixed timestep for fast bodies (see physics-tuning).
Camera snaps and induces nausea → smooth/lerp the follow, add a deadzone, clamp to bounds.
Difficulty wall from bad teaching → introduce one mechanic per area before combining them.

Composition (build it from these skills)

Controller body: godot-2d-movement (Godot CharacterBody2D); for other engines use the engine core + physics skill (unity-physics, phaser-arcade-physics, pygame-core).
Levels: godot-tilemap / unity-tilemap-2d for geometry; level-design for layout, pacing, and teaching order.
Feel/physics: physics-tuning for timestep, CCD, and stability.
Input: input-systems for buffering, rebinding, and gamepad support.
Polish: audio-design for SFX/music; the engine animation skill for squash/stretch.
Process: prototype-fast to greybox the controller before building content.

References

For jump math derivation, a full feel-tuning table, corner correction, moving/one-way platforms, and camera follow, read references/feel-tuning.md.

FAQ

What does the platformer skill do?

Build a 2D platformer: run/jump control with coyote time, jump buffering, and variable jump height, plus tiled levels and hazards. Use for a platformer or Mario/Celeste-like, or tuning jump feel.

How do I install platformer?

Run npx skills add https://github.com/gamedev-skills/awesome-gamedev-agent-skills --skill platformer in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/platformer/ (personal) or .claude/skills/platformer/ (project).

Which AI agents can use platformer?

Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.

Is platformer safe to install?

Security partners have reviewed it: Gen Agent Trust Hub passed; Socket passed; Snyk passed. As with any skill, read the SKILL.md and bundled scripts before installing.

Who maintains platformer?

It is published by gamedev-skills in gamedev-skills/awesome-gamedev-agent-skills. It has 6,364 recorded installs.