The invisible walls of Duel at Dawn need to be extended. When you collide with it on the north (I think) side of the map, it turns your ship into one of the big metal structures causing you serious damage. It also adds confusion (we had all 4 ships of a 2v2 trying to get around that structure, all colliding).
Ontop of that, can there be some kind of indicator of where the invisible walls are? Maybe some small text at the top of the screen with a warning or something.