Week 2 -- 2D Arc: Movement, Sprites & World Building

Date: April 24, 2026 Arc: 2D Game (Week 1 of 3)

Featured Game: Gunstar Heroes (1993, Treasure / Backbone remaster)

Brian produced the remaster. Play 2 minutes on the projector.

• What to notice: expressive sprites, tight movement, how the level scrolls, how responsive the controls feel.
• "This game was made by 7 people. Your team is 1. But the fundamentals are the same."

Play-Test Spotlight

Selected student shows their customized tutorial from Week 1.

Learn

Sprites

• What they are: 2D images that represent game objects
• Animation frames: a series of images played in sequence to create motion
• Hitboxes: the invisible shape used for collision detection (often smaller than the visible sprite)

Platform Behavior Deep Dive

Property	What it does	Try this
Gravity	How fast the player falls	Low = floaty moon. High = heavy brick.
Max falling speed	Terminal velocity	Prevents infinite acceleration
Jump speed	Initial upward velocity	Higher = bigger jumps
Acceleration	How fast you reach top speed	Low = ice skating. High = instant response.
Deceleration	How fast you stop	Low = slidey. High = precise stops.
Max speed	Top running speed	Affects level design -- wider gaps need more speed

Key Vocabulary

Term	Definition
Sprite	A 2D image used to represent a game object
Animation frame	One image in a sequence that creates animation
Hitbox	The invisible collision shape of an object
Parallax scrolling	Background layers moving at different speeds to create depth
Game feel	How responsive and satisfying a game's controls are
Tiled sprite	An image that repeats to fill an area (great for ground/walls)

Build

1. Start a new 2D project (fresh, not the tutorial).
2. Create or choose a player sprite. Set up platform behavior.
3. Build Level 1: ground, platforms, walls, pits, a background.
4. Tune movement until it feels good: gravity, jump height, run speed, friction.
5. Add at least one decorative/environmental element (trees, clouds, crates).

Play & Feedback

Swap and play. Feedback prompt: "How does the movement feel? Too floaty? Too stiff?"

Resources & Further Reading

• GDevelop Sprite Editor Guide
• GDevelop Platform Behavior
• Game Feel by Steve Swink -- the definitive book on game feel
• Juice it or Lose it (GDC Talk) -- classic talk on making games feel good
• OpenGameArt.org -- free game art assets
• Kenney.nl Assets -- high-quality free game assets

Stretch Goals

• Custom pixel art character (see the Pixel Art Worksheet).
• Parallax scrolling background.
• Animated idle/run/jump states for the player sprite.