Depends on whether or not its a maze game or a platformer. In a platformer, it's very hard and requires lots of coding. For a maze game, it's slightly easier. In a Step Event, you tell your enemy to "Step Towards Point Avoiding Objects", and have it avoid only solid objects, and make the walls and the person you're playing as solid. Then, the point you tell your enemy to step to is "whateveryourobjectis.x,whateveryourobjectis.y,". They should follow you while avoiding the walls and obstacles.
Oh, I'm making an RTS based off of Bionicle.
Click here to see a screenshot. It's VERY early in production, but the finished product will hopefully be good.