GridFall is a falling-block grid puzzle: tiles drop into a well, you slide and rotate them, and matching lines or groups clears them for points. Before we write a line of code, you need the mental model Godot runs on.
▸ By the end of this lesson: A running empty Godot project and a clear picture of the finished game
1.1The finished game, described once
Keep this picture in your head for the whole 2D course. Every lesson bolts one piece onto it:
The well — a fixed grid, 10 columns wide by 18 rows tall, that pieces fall into.
The piece — a small shape (1–4 cells) that spawns at the top and falls one row at a time on a timer.
Player control — move the piece left/right, rotate it, and soft/hard drop it.
Locking — when a piece can't fall further, its cells become part of the well.
Clearing — any fully-filled row is removed, everything above shifts down, and you score.
Escalation — the fall timer speeds up as your score climbs.
Game over — a new piece can't fit at the top.
Why this game
GridFall touches every core 2D skill exactly once: grids and coordinates, input, timers, collision-by-logic (not physics), spawning scenes, UI, and state. Master it and you can build most 2D puzzle and arcade games.
1.2The one idea Godot is built on: nodes in a tree
Everything in Godot is a node. A node does one small job: draw a sprite, play a sound, detect a collision, hold a timer. You compose nodes into a tree, and a saved tree is a scene. A scene can be dropped inside another scene like a Lego brick.
For GridFall we'll build a few scenes: a Cell (one square), a Piece (a shape made of cells), and a Main scene that owns the well and glues everything together.
GDScript vs C#
We use GDScript, Godot's built-in Python-like language. It's the fastest way to learn the engine, ships with every install, and every example here runs as-is. No .NET setup needed.
1.3Install & create the project
Download Godot 4.x (the standard build, not the .NET build) from the official site and unzip it. It's a single executable — no installer.
Launch it. On the Project Manager, click + Create.
Name it GridFall, pick an empty folder, leave the renderer on Forward+ (or Mobile if you'll target Android — GridFall runs fine on either), and click Create & Edit.
You're now in the editor. The big center area is the viewport; the left panel is the Scene tree and FileSystem; the right is the Inspector.
1.4The editor regions you'll actually use
Scene dock (top-left): the node tree of the currently open scene.
FileSystem dock (bottom-left): your files. Scenes are .tscn, scripts are .gd.
Inspector (right): properties of the selected node.
Bottom panel: Output, Debugger, and the Script editor tab.
Top-right run buttons: ▶ runs the main scene, and the clapperboard runs the current scene.
Sanity check
Press ▶ (or F5). Godot will ask you to pick a main scene since none is set — click Cancel for now. If the editor responds, your install works. We'll set the main scene in Lesson 3.
Checkpoint — expected state
Godot 4.x installed and a GridFall project open.
You can name the four editor regions above.
You can describe the GridFall loop from memory: fall → move → lock → clear → escalate → game over.