When I hover over the bottom center to populate the menu, it disappears too quickly on me. Extend the menu display during the hover state to at least 5 seconds. Alternatively, you could have the menu display until the user navigates away from the bottom center.

As a user
When I hover over the bottom center
Then the menu should be displayed for 5 seconds

Or

As a user
When I hover over the bottom center
Then the menu should display until I navigate away from the bottom center area.