New game concept I had -- is it too similar to anything?

So, to preface this: there are too many board games for me to know them all. I had this great concept last night (it came into my head near fully formed! It was awesome!), but I don't know if it is too similar to anything out there, so I will pitch the question to the masses here. Read the concept I'm about to outline and let me know if its too similar to something already out there.

Its a co-op game. The players all find themselves in an old, spooky sort of castle. How they got there is irrelevant at this time (unique characters will be developed if/when I flesh this out). The players quickly discover that the castle is haunted by the malevolent Dullahan (headless horseman, but in this case with no horse). They must escape the castle, but they discover the front door is locked and they must find either a key or an alternate exit, all while being pursued by the Dullahan, who only wants to add heads to his collection.

Mechanically it will use Tile Placement and Card decks. The starting tile will be a larger, 8x8 tile representing the grand entrance. 4x4 Tiles are then laid face down around the grand entrance, each tile representing a new room or corridor. The tiles will all be marked on the back with the locations of entrances etc so that everything lines up when tiles are placed during setup.

Players move between rooms, exploring as they flee the Dullahan. There will be traps between rooms that either need to be disarmed or will hurt/maim/kill party members. There will also be encounters with other ghosts -- previous Dullahan victims, banshees announcing the imminent death of a party member, and the like. The game ends when the survivors escape the castle, or when they are all dead.

Because I hate player elimination (nothing is worse than starting a game and then having to wait for an hour while not playing after you've been killed!) I will add a player mechanic wherein the killed players may return as ghosts -- either to add to the haunting or to try and lead their friends to escape.

Searching rooms will yield tools that can be used to stall the Dullahan or remove ghosts. The Key(s) to escape will also be found this way.

So, what do you think? Is there anything similar to this out there? I don't know enough about this particular genre to say either way. Its primarily an escape co-op, with little emphasis on fighting. More a puzzle game, I think.