This gave me flashbacks to Gnome 2 and how much I loved it.
The HUD(?) was a great concept allowing easy Dutch within an apps menus.
That's hardly innovation though since most DEs over the past 2+ decades that I can think of would let you move the taskbar (if they had one) anyway.
The problem with Unity was that it was buggy as hell, and the launcher was really badly styled. Huge gaps between icons, the search filter was unusable, etc.