World 3 / Quest 10

Hero Jumps

Gravity. Platforms. A jump that feels right. The start of a real game.

You’ll learn

• How a platformer works: gravity, ground, jump
• Why a game is now several files, and how Coach keeps them tidy
• Tuning a jump until it feels good (the most-argued-about thing in games)

Briefing

Start prompt

Steps

1. 1

   Rules of the world

   Say the rules: gravity pulls down; the hero stands on platforms; arrow keys run left/right; the up arrow (or SPACE) jumps — but only when standing on something. That last rule is what separates a platformer from a flying game.

   Say this to Coach

   Rules: gravity pulls the hero down. Platforms are solid — you land on them. Left and right arrows run. SPACE jumps, but ONLY when the hero is standing on a platform. Build a hero (use my art if I have it, or a rectangle), a ground, and two floating platforms. Nothing else yet.

   Copy
2. 2

   Play, and find the floor bug

   Run it through the Studio Server. Jump around. Jump onto a platform from below — did you go through it, bonk it, or land on it? Jump off the edge of the world — what happens? Say What You See for anything weird, with a screenshot.

   Say this to Coach

   I expected the hero to land on the platform, but it fell straight through. (Screenshot attached.) It happens when I jump onto the platform from underneath.

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3. 3

   Tune the jump

   This is the fun part. Ask Coach what the current jump numbers are (jump power and gravity). Then change ONE at a time: "Make the jump 20% higher." Play. "Make gravity a little stronger so it's less floaty." Play. Keep going until it feels good to you.

   Say this to Coach

   Tell me the current jump power and gravity numbers. Then make the jump 20% higher and I'll test. We'll keep tuning one number at a time until it feels right.

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4. 4

   The camera

   Right now the whole level fits on one screen. Real levels are wide. Ask Coach to make the level 3 screens wide and make the camera follow the hero. Then run to the far right and see what's there.

   Say this to Coach

   Make the level 3 screens wide, with platforms spread across it. Make the camera follow the hero so the screen scrolls as I run. Keep the hero from leaving the level on the left or right.

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5. 5

   Face the right way + the double-jump decision

   Make the hero face the direction it's running (flip the picture). Then a design decision: should there be a double jump? Ask for options on how it could work (once in the air, only after a coin, never). Pick. Or don't add it — that's a design choice too.

   Say this to Coach

   Flip the hero to face the way it's running. Then give me 3 options for a double jump — how it could work and why a designer might choose each. I'll pick one or say no.

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6. 6

   Checkpoint and file tour

   Ask Coach for a tour of your files: what's in index.html, what's in game.js, what's in assets. You don't have to understand the code. You do have to know where things live. Then checkpoint 'hero-jumps'.

   Say this to Coach

   Give me a quick tour of my platformer's files — what each one is for, in one sentence each. Then save a checkpoint called 'hero-jumps'.

   Copy

Side quests +10 XP each

Stuck?

• Hero falls through the floor? Classic. Screenshot + "I expected the hero to land on the ground, but it fell through."
• Can jump forever in the air? Say what you see: "I can jump again while in the air. I only want to jump from a platform."
• Camera is jittery? "Make the camera follow smoothly instead of snapping."

More ways to get unstuck