Thanks for your feedback, actually they aren't attracted. I suppose the movement mechanisms feel weird to you, that's interesting to know :)
The intent idea is to provide players with a sense of pride and accomplishment for unlocking different heroes use the walls to put your spheres in a position so they can be on the squares when your main one is next to the door so you go through it and finish the level. It may not have been obvious enough, again interesting to know :P