Missile turrets hint:
Upgrade your missile turrets to “Eagle Scout” turrets when placed. They inflict more damage and have a greater range.
Linked lasers hint:
Build about fifteen and twenty lasers near each other, then select one of the lasers near the middle and choose the “Link Nearby Lasers” option.
Linked defense towers hint:
When enemies approach, link plenty of defense tower together. You can link them by pressing