The German adventure site Adventure-Treff has the scoop, and Haggis from The Pumpkin Post has translated it:
The source of inspiration for Ghost Pirates is the Pirates of the Caribbean ride in Disney World. The game, however, will not at all be a copy of Ron Gilbert’s Monkey Island. The three protagonists will find themselves in a spectral form, and this will play a major part in the puzzle design. For instance, collecting objects isn’t possible at first, so the player has to find different ways to deliver an object to its destination. Similarly, communication with non-ghosts is only possible indirectly. Special skills like the option to walk through walls, will also play a part in puzzles. There will also be cooperative puzzles, similar to those in Day of the Tentacle, for instance.