There are a ton of people who are going to hate me for telling you this but a good way to make sure you funnel opponents into killzones is to design a trap system like this
The colonists will walk straight through the two doors and rearm the traps safely during peace time and after battles. However invaders will path the long way through the center preferring the open path to the base wherein there could be a handily placed kill box. Only sappers are immune to this layout. Invaders don't seem to be wise enough to want to bash down the doors, instead they choose to traverse the longer path through the death ridden hallway. These traps are always going to kill sythers, and usually strong enough to take out 1-2 centipedes even before they hit the kill box because they trigger every last trap in the hallway.
This particular sample is very modest. Redundant systems of this type are very strong, and only require blocks to rearm, which is very cheap indeed on most maps.
The colonists will walk straight through the two doors and rearm the traps safely during peace time and after battles. However invaders will path the long way through the center preferring the open path to the base wherein there could be a handily placed kill box. Only sappers are immune to this layout. Invaders don't seem to be wise enough to want to bash down the doors, instead they choose to traverse the longer path through the death ridden hallway. These traps are always going to kill sythers, and usually strong enough to take out 1-2 centipedes even before they hit the kill box because they trigger every last trap in the hallway.
This particular sample is very modest. Redundant systems of this type are very strong, and only require blocks to rearm, which is very cheap indeed on most maps.
