In South East Europe, “Heat Wave” you return to some familiar grounds, however changed in a way in which it is aptly named. The lake which previously existed here has completely dried up, still keeping you from placing turrets in this area, however opening up a new rout of attack against your base. The ground units you will face in this level will be supplemented by aircraft at wave 15, with 30 total waves to fight your way through.
Turret Placement should focus on creating a thick defensive line near the final convergence before your home base, with turrets stretching from the center of this meeting point both north and east to cover the approaching units. AA turrets can occupy the island of buildable space in the dried up lake.
Starting off its time once more for initial investment of Machine Gun turrets, placing them right at the point where the roads meet next to your base. Try to have 5 maxed out by the end of level 10.
Continuing into the level, make sure you have your AA placed by the end of wave 14 to accommodating for the first groups of aircraft at 15. Other than that, make sure you save up for an X-Weapon which can be placed next to some upgraded turrets for boosted firepower. Like the previous mission and the ones following, these are your ace in the hole.
Onwards from wave 20, save up to place an Inferno turret on each of the main paths that meet before your base to manage their flow. By wave 30 you should have 2 second level AA turrets, a second level upgrade to your X-Weapon and the rest of your money spent towards level 3 Cannons.
Victory Point Spending
Now is a great time to put a third point into the Buy upgrade, giving you the biggest possible starting funds which can make all the difference from here on out. Third level AA turrets are also valuable considering their weaponry will be needed and its best not to have to waste space on several level 2 AA guns where a couple level 3s will do just fine.
Everything should now be maxed out except for Firestorm, X-Weapon and Repair which should be at level 2.