As the title, I've been thinking on a game concept I've had for a while now and was wondering if I could get some input and perhaps bounce some ideas of the community.

The game concept is a single player (possibly co-op) game that works similar to Brothers: A tale of two sons.

That is to say, it is a single player game that controls two characters simultaneously.

It will be a top-down game that shares resemblance to Legend of Zelda in terms of gameplay with the addition of a second character to control.

Each character has their own strengths and weaknesses and they work together to achieve their goals, and the player must decide how to control them to do that.

The concept I was initially thinking of was that of a young girl and a spirit who is bound to her.

The spirit would be able to travel through most walls, pick up or interact with smaller objects, etc.

The girl would be able to push heavy objects and travel between rooms (as the spirit is tied to the girl).

Of course, that's just the beginning of the concepts I am imagining.

For example, the spirit couldn't enter areas which are "sanctified", which the girl can (and possibly desecrate the area to allow the spirit to travel), or the spirit could bypass dangerous traps to disable them.

Other challenges come in the form of enemies, such as creatures that would attack the girl or priests/shaman that would seek to exorcise the spirit.

Abilities could be unlocked for the two along the way, such as the girl gaining a projectile weapon, or the spirit being able to possess weaker creatures in order to interact with the world similar to the girl, but in areas she can't normally reach.

It's ultimately a puzzle/adventure game similar to Legend of Zelda, though far more oriented on puzzles, while also having that double character control of Brothers.

It also has the potential to have a co-op mode, which could possibly be used for more difficult puzzles and giving control of either the girl or the spirit to either player.

What do you think?