Played it this morning and had a lot of fun.
It's kind of linear, you'll have to make your way through corridors, stairs and little arenas, decks have floor numbers which help, but sometimes it's a little bit confusing (do i have to break windows and get to an area that was not intented by the author of the map ?).
The ship is in total panic, there is fire, broken furnitures, angels screaming, it has that very nice little tense of urgency going on, get out of here !
I found also that your level felt a bit like dead island, and could easely be a part of the main story, don't know if you thought of that while building this game mode.
Any way i really thought that Jacob would be the main target and was eagerly waiting for the moment where i could finally reach him, the first encounter he was mainly mocking at me.

The boat is a huge one (very impresive, kudos for that) and the path you need to take is very twisted, (in a good way) difficulty was spot on for me, there was a sufficient stock of ammo and weapons even if i nearly died two or three times, especially when angels are rushing towards you and that you're trying to reload, it's quite the scary thing.
But i finally made it and manage to escape, great feeling !
It's really the kind of map that i will replay with pleasure in the next days, rush mode time attack with guns blazing in mind or wandering around looking for every detail.