The Lurker and the Invisible Caster are enemies that you need to block first before you can attack them. However, using a detector against them reveals them, allowing you to hit them with Snipers and Casters. Detectors have a short cooldown time, but carry limited use charges, so use them well!
Place Operators On The Top Left
There are 3 enemy camps in this map and only 1 entrance to your base. While it might be tempting to funnel all of the enemies at the bottom-most lane, it is recommended that you place some Operators near the top-left spawn point for more control over enemy numbers.
Defend Against The Veteran Butchers
The latter enemy waves will spawn Veteran Butchers, an enemy with high HP and RES. If it manages to punch through your defenses, pull back your forces on the upper left and use the extra deployment points to defend against the Veteran Butcher.