When comparing the difficulty select menu in the original MS-DOS release of Jazz 1 to OpenJazz, there are some differences that can be found in still images itself of those menus:
MS-DOS:

OpenJazz:

Now the level select screens:
MS-DOS:

OpenJazz:

The blueish main menu animated background is missing in both OpenJazz's level select & difficulty select menu items.
The animations or could you say fading-effects for the menu items in both the level select & difficulty select menu are also not present as of yet in OpenJazz.
When comparing the difficulty select menu in the original MS-DOS release of Jazz 1 to OpenJazz, there are some differences that can be found in still images itself of those menus:
MS-DOS:
OpenJazz:
Now the level select screens:
MS-DOS:
OpenJazz:
The blueish main menu animated background is missing in both OpenJazz's level select & difficulty select menu items.
The animations or could you say fading-effects for the menu items in both the level select & difficulty select menu are also not present as of yet in OpenJazz.