Linear maps: This is about exploration. Linear maps do have some exploration, although it's merely finding a startingpoint of a rollercoaster or looking in corners for some items (Uncharted). Fallout is randomly random you can go anymore you like. There is a lot to explore. GTA is also openworld, but it's pointless there is nothing to explore in their big citys only cars and pedestrians.
Linear enemy's: No matter how smart an enemy is, it all comes down to their spawnpoint. If you know where they are spawning it becomes a lot easier. Many games have fixed enemy's fallout, deus ex, cod, but there is one game I'm aware of and that is Left 4 Dead with random spawnpoints.







