From Black Mesa: Wiki

The Main Menu seen while the player is not in game.

Overview

• Resume Game*
• New Game
• Load Game
• Save Game*
• Developer Commentary
• Achievements
• Game Options
• Options
• Quit

An * indicates that the option is only visible while in game.

Game Options.

Game Options

• Custom BM mod options are toggled on/off or its parameters are changed through this GUI interface.
• Players can add customize the panel by modifying a simple script. The options in the panel are reloaded every time it is opened so changing the options can be done in real time.

Background

Black Mesa will feature 3D backgrounds that changes as you progress through the game. It's similar to those we can see in Half-Life 2 and the episodes. [1]