Hiya, I took a look at your game and the enemies are bullets that rotate towards the player so they would ignore the wall. I don't know how you want to use the line of sight behaviour, but as an example you can add the line of sight behaviour to the enemy. Then you say in the logic, if enemy has line of sight of player, enable the projectile, if enemy does not have line of sight of the player, disable the projectile. This would create something where the enemy only moves if you are close. It really depends on how your game will work. You can read more about LOS in the manual.