Okay, let's create a basic 2D platformer level featuring Yoshi. We'll use HTML, CSS, and JavaScript with the HTML5 Canvas for rendering. This will be a simple starting point.

Now you can see a basic scene. Use the Arrow Keys (or A/D for left/right, W/Space/Up Arrow for jump) to move the green rectangle (representing Yoshi) around the platforms.

Okay, let's replace the block with a drawn Yoshi shape and make the level longer and a bit more detailed. We'll also implement a simple camera to follow Yoshi.

Now you should see:

1. A crudely drawn Yoshi instead of the green block. It will flip direction based on movement.
2. A much longer level that extends beyond the initial screen width.
3. A camera that follows Yoshi horizontally as you move through the level.
4. Some simple cloud and bush decorations in the background.

Use the same controls (Arrow Keys or A/D/W/Space) to explore the extended level.