Problems with light (that weren't in the old exporter...)

For some reason now the shapes I make in blender look really strange in game. For some reason they are really lit up and the edges are really defined. Some sides are almost black and others white and the colors change when I move.

Is there any way to fix this?

By the way, as I mentioned in the topic title these problems were not in the earlier version of the exporter. I have many models from before, so I made the same model with the same texture and everything. For some reason it looks way different in game (I tried to take screen captures, but my computer sucks and they all came out corrupted).