Click on the green flag to generate new art. Turn on turbo mode for a quick rendering. Here is an inspiration (remix it!) to create a project for day #1 of Genuary 2025 (https://genuary.art/) which prompt is "Vertical or horizontal lines only." Just use a sprite as the mask to draw vertical and horizontal lines.
See forum post about Genuary 2025: https://scratch.mit.edu/discuss/topic/796958/ For the adacraft version: https://www.adacraft.org/project/418642320381968592