I've seen this kind of concept before, but it's not a bad idea, however...
Well, the fact that the characters don't share the same location is really confusing, might as well just make it a two-window-game, i.e. black guy on the left, white guy on the right(or something along the lines) and just activate/deactivate which one is moving. Would have resolved a lot of the confusion.
Is the second level suppose to not end? I get to the box(which i assume is the door to the next level) but nothing happened. Same with the level selection, i can't get level 3 and beyond to work. If you haven't finished them yet(which i assume based on your description) you should have a note in the game itself that these levels don't work yet.