There's a bug on the latest snapshot that causes a world's info to appear above the buttons "Play selected world" and "Create new world" in the world selection screen. This error is purely aesthetic, and doesn't affect the functionality of the buttons. The text isn't gray, either; it appears as the texture of the dirt block background. Attached is a screenshot taken via Minecraft's own screenshot system (F2). The error occurs both on full screen and windowed mode.