Platformer Editor

Use the Platformer editor to build a 2D game with a running and jumping hero, pickups, foes, doors, and goals. The editor has forms for the game’s settings and rules. You can add ordinary Myth resources and Logic as the game grows.

To add platformer movement to an existing Scene, assign Platformer parts to ordinary 2D Objects. That workflow can begin with a Body and ground Surface without first creating a game through this editor.

Prerequisites

Open a 2D project and save a checkpoint. This guide follows the Mercury 1.0.1 development interface inspected on October 5, 2026. An earlier installation with the same package version can have different controls.

Make the First Room

1. Choose File > Platformer Editor… to open the editor. When the project already has platformer settings, you can also open Platformer Game in the Resource Tree.
2. Choose Make a Platformer Game. The engine adds platformer settings, a starter Tileset, and a room with a floor, a Player, and a Goal. In an existing platformer project, use Rooms > Add a room to add another room.
3. Open Rooms, select the new room, and choose Play from here. Walk across the floor and reach its goal before changing the layout.
4. Check the project’s Start Scene in General Settings. Creating a platformer in an existing project can preserve its previous start Scene. Play from here tests the selected room without changing that setting.
5. Save, reopen the project, and confirm that Platformer Game and the room are still present.

Expected result: the selected room runs as a platformer and its floor supports the player. Starter pictures and plain boxes are enough for this first movement check; assign finished art before publishing.

Find the Right View

View	What you change
Game	Game settings, lives and health, cards, touch buttons, HUD, camera choice, tile size, and art scale.
Hero	Movement presets and dials, with a live test room and measurements of the hero’s reach.
Rooms	Room size and behavior, start room, doors, music, backgrounds, and the link to edit a room’s contents.
Things	Role Objects and their Sprites, the pictures used for things the machine creates, changing tile pictures, and Art Check.
Look and Sound	Music, individual sound cues, and effects for machine events.
Rules	Flags, counters, triggers, and doors that wait for a condition.
Test	Play, Pose Board, room proofs, difficulty estimates, rougher playtests, and room generation.

Room painting and placement happen in the Scene Editor. The Platformer editor opens that Scene through Rooms > Edit room.

Tune the Hero

Open Hero and choose Start from a feel. Try a preset, then change one dial at a time while the test room runs. Use Everyday dials for the initial adjustments and All dials when you need the full set.

Start with run speed, jump height, and time to the jump’s peak. Then check stopping, turning, landing, and short jumps. A fast hero can cross a small room before you have time to inspect the movement. Keep a reachable floor and ledge in the test layout.

Read each dial’s unit. A height shown in tiles depends on the game’s tile length; timing fields use seconds. Use the reach display to compare the current feel with an intended gap, then play the actual room. A measured jump doesn’t include every hazard, moving platform, or player decision in that room.

Use Start again to reset the Hero test room. When the game has multiple players, Each player’s feel can give one player a preset of their own. Check each player’s controls and movement before testing cooperative rooms.

Set Tile and Image Scale

Game > Tiles and art size has three separate controls:

Control	Effect
Tile size (m)	The world length of one machine tile, from 0.125 to 8 metres. Every platformer room’s Scene grid follows this setting.
Art scaling	Pixel-perfect retains the artwork’s pixel treatment; Fit to body fits the visual to the machine body.
Art pixels per tile	The source-image density used for platformer art, from 1 to 256 pixels per tile.

Choose tile size before laying out many rooms. Changing it updates their grids; check existing placements, collision, framing, and art afterward. Project Pixels per Metre is a separate rendering setting. See world units and image scale.

Give the Game Its Pictures

Open Things and find a role such as Player. If it has no Object, choose Make its Object. Choose a Sprite for the Object, or use New character sheet to make a sheet with rows for the clips the role needs. Open Object and the Sprite Editor to draw or import the pictures and configure their animation.

Check the Object’s feet, body size, and clips against the running game. A picture can look correct while its collision body is too large. Things > What the machine makes while it plays assigns Objects to generated looks such as projectiles or other runtime parts. The picker and its fallback describe which Object is currently shown.

Things > Tiles that change assigns the picture for states such as a used box or broken tile. Keeping its picture, selecting a replacement tile, and making it disappear are separate choices.

Run Art Check after assigning the resources. Every look needs art (placeholders block Publish) controls whether missing pictures prevent publication. Use Pose Board and room checks to inspect the poses and actual level use.

Choose Sound and Presentation

In Look and Sound, choose game Music and a project Sound for each cue you want to replace. A cue can also resolve a Sound named for it; the row reports that assignment. The built-in sound is the fallback when no project Sound is chosen or found. Use the row’s play control, then trigger the same cue in the game.

Add an Effects row for a machine event. Choose a project Particle or a built-in burst, and configure its Sound, shake, flash, or short freeze where offered. Test repeated events and reduce effects that obscure the player’s landing or cause uncomfortable motion.

In Game, choose the platformer camera framing or the Scene’s own camera. Add the HUD with Add the HUD (hearts, coins, lives, keys, clock). It creates Screen UI Text Objects in the rooms, which you can restyle in their own editors. Room-specific music, backgrounds, and camera shaders are in Rooms > Look and music.

Check and Publish

Build a short route through one room, then connect a second room. Add rules after ordinary movement and door travel work. Run room and art checks, play from the game’s real start Scene, and test an export.

Troubleshooting

Symptom	Check
Play opens the old game	Check General Settings > Start Scene; use Rooms > Play from here to isolate the new room.
No ground to paint	Create Platformer Tiles, or give an existing Tileset the required Gameplay Types.
The hero’s size or speed changes unexpectedly	Compare Tile size (m), image scale, body size, and the unit on the changed dial.
Plain boxes appear	Assign Sprites to the role Objects and check the generated-look assignments.
A room’s changes aren’t in the exported game	Save, check the start Scene and room connections, and export again to the intended folder.
The editor reports a problem	Fix the named room, reference, or form field before relying on its preview or proof.