Your first level in 15 minutes

Open the editor. It runs entirely in your browser: nothing is uploaded until you submit a level. Press F1 in the editor at any time for its help.

1. Start from something

Start from the example level (a short level you can take apart) or File › New level. Give it a name and set the terrain (space, jungle, ice, desert, sea, lava, swamp or city): it picks the ground, buildings and colours when you do not bring your own art.

2. The strip

The level is the tall strip in the middle: the bottom is the start, time goes upward. The timeline on the left is in seconds. Scroll with the mouse wheel; drag the scrubber in the top bar to jump.

3. Ground: buildings, turrets, rocks

Drag items from the palette on the left onto the strip: houses and bunkers are solid (touching them is fatal), turrets and tanks shoot. High rocks are solid walls you can paint with the brush to make canyons; barriers are invisible walls for the edges of your own art.

4. Waves

A wave is a group of ships that enters at a time, follows a path and shoots. Drop a wave on the strip, then set its ships, count, path and timing in the inspector on the right. Mirror a wave to get the same pattern from both sides.

5. The boss

Every level ends with a boss: choose its attack style, hit points and when it arrives (a time, or after the last wave).

6. Preview, fix, repeat

Press ▶ Preview (or F5) to watch the level play. The pill in the top bar shows whether the level is valid; click it to see the problems, each with its line.

7. Save and share

File › Save keeps the level file (.md). File › Export level + pictures gives a .zip with the level and its pictures: that is what you submit.