I think you know how to begin the clock. To set alarm, click the arrows on the bottom right, and click button next to them. When alarm rings, click the yellow button to stop it. To change between 12- and 24-hour, click the button on the bottom left. To change the clock's colour, click the one above it. To change the colon flashing speed, drag the slider on the top left.
Inspired by IKEA, full credit to them. It's been a while, huh! Kienzle Electronic Wall Clock with Hour strike is here: https://scratch.mit.edu/projects/1163735358/
