Anti-Air

Overview

 * The Anti-Air is a tower, specified for air targets.
 * It's the cheapest, but the most effective tower against air enemies.
 * It has a tremendous range (second after the Violator, while Rockets are on the third place by this indicator).

Notes & tactics

 * The Anti-Air can effectively make a lot of earlier maps with air foes much easier, although it shines mainly against the hordes of Spore Pods in Arc Islands, where they're the most needed (and most efficient) towers. Its cost efficiency is completely unmatched when it comes to air enemies.
 * The tower gets more damage per resource when overcharging it (20% more gain than building more level 3 AA towers), being the only tower in Sanctum 2 with such an efficiency paradox - building level 3 AA towers gives ~333 damage per 100 resources, while overcharging gives 400 dmg per 100 res.
 * That's why in most maps with air lumes of the game it is better to have one Anti-air (AA) tower, which is just overcharged according to the health of the lumes.
 * However, it has a finite attack speed and at a certain point further overcharge might become mostly unhelpful. If the displayed damage is more than 1/6 of the max health of the most-healthy types of air lumes in the map, then it might become better to add another AA tower, if it is needed (e.g. in 5-4: Laser bridge in the wave with Spitflies, in 5-3: Jellyfish cove for some of the waves, in the 8th region (Arc islands), and even for 4-3: The Wilderness, since there in the last wave Spitflies might need a bit more kiting to kill with a sole AA tower), although a Range spire often can overcome such a need with sometimes some overcharge and trickiness in tower positioning, and having effective alternatives of this tower might also reduce the needs of a 2nd/3rd one. Another scenario is if the map is huge and a single AA hardly can reach the needed area where the flyers pass. In a part of the cases this can be overcome via a Range spire. These things, however, are more related to the Easy & Campaign mode, since in Survival it is generally useless to build more than one AA in all scenarios.
 * Although extremely powerful, this tower is able to target and hit only the 4 usual (non-boss) flying enemies - Spitflies, Bliskeblaskes, Spore Pods & Healers, since the boss Fiskeplaske is invulnerable to it. Ground lumes would suffer some area-of-effect damage if close to explosions, caused by the tower, but would never be targeted by the tower.
 * If the enemy is flying close enough to ground enemies, the Anti-Air explosion may hit them as well, potentially dealing massive damage.
 * Like all projectile-using towers, the Anti-air suffers from some sight obstructions like walls & rocks, so it is good to place them carefully. In this particular case, however, the only towers that would produce obstruction appear to be very high ones, like another AA towers, Violators and probably the ACP & Orbital strike relays (depending also on how high the lumes fly), which is usually easy to deal with via some careful tower positioning. If there are wall/rock obstructions, the tower would either not fire or would lose some rockets that to explode into the obstruction.
 * Projectile-towers are the Scatter lasers & the ones with targeting system.
 * Like the the other projectile-using towers & the ACP, if a player is sitting on the tower, when it fires, it will push and move the sitting player.
 * While the missiles fired from the tower would technically mean simply that a level 1 AA deals 800 damage per attack, level 2 - 2800 & level 3 - 6000 damage per hit correspondingly, in some scenarios things might become trickier
 * Against lumes with armour the damage reduction applies to every single rocket fired - that's how a Bliskeblaske, that is in a defensive state would not take any damage from a level 1 Anti-air & a level 2 tower with no more charge. A level 3 AA would have its damage reduced by 750*6=4500 and then the curled Bliskeblaskes would take just 1500 damage. If nearby armoured ground lumes that are close to flying ones also get damaged by the explosions, they would also have the damage reduced by their own armour per rocket exploded, e.g. a Heavy pup nearby would take up to (1000-300) x6 = 4200 damage.
 * Another scenario is when the Hydra hunter feat is enabled. While this one is usually not that noticeable, it might lead to a lume not executed as expected, e.g. if in a solo play with the Titan Slayer & Hydra hunter feats enabled a Spitfly is hit by a simple lvl 3 AA in the Campaign mode, it wouldn't die, because the 6 rockets have a slight delay between each other - it will survive, although with a minimal amount of health. A little overcharge then would do the job, e.g. to 1050, also resulting in less wasting of damage in the air.
 * If obstacles cause some missiles to get lost (to be destroyed into them), the flying lumes would get hit just by the remaining ones - e.g. if in Jellyfish cove some projectiles get destroyed into the trees, the Spiflies/Healers would get hit by the remaining for a lower amount of damage.
 * If the target gets killed while the tower has fired missiles to it, the fired missile cluster would auto-destroy itself, which is usually just a small issue, that occurs more frequently if the tower is buffed by a Range spire and if there are multiple Anti-air towers. With a bit more careful positioning, it can be prevented, e.g. with positioning of the tower close to the spawn point. In comparison, the Rocket tower would simply lose aim of the sent rockets if its target gets killed, continuing in a linear direction.
 * In the maps of the Arc Islands there are invisible obstacles, that could easily cause the AA to fire and crush rockets while trying to reach a targeted lume. This could be resolved via using a separate Range spire for the Anti-ari
 * Some comparisons with other towers
 * The Violators are among the best alternatives of the Anti-air, somewhat similarly to the situtation in Sanctum 1. However, their low fire rate quickly shows weaker capability, despite of the long range superiority. While the level 1 Anti-air doesn't appear to be that superior, the level 2 & 3 tower shows a high domination for the resources spent.
 * The Rocket towers as somewhat similar in action would easily fall much behind the Anti-air with the game's progress. While it is still one of the best alternatives of the Anti-air, the Rocket has smaller range, costs more, has less damage per cluster of rockets, while also less projectiles per cluster and a lower fire rate. If there aren't too many flying lumes, they can finely substitute the Anti-air, but should the flying things become too many and problematic, Rockets may no longer be used as an effective alternative. One interesting phenomenon occurs randomly to both these tower types - if an enemy is flying too high or too far, the projectiles might start to roll in silly circles around it until it finally goes closer and takes damage, which sometimes happens with the secondary fire of the Rex as well. This usually feels worse when it happens with the Rocket tower, since for the Anti-air the "rolling" rockets would explode faster, from a further distance.
 * The Focus is way behind the Anti-air, regardless of any buffs, upgrades, overcharge and so on - even in the brightest scenarios the Anti-air would easily deal more than 8 times the damage of the Focus vs the flying things per resource spent, while also the noticeably longer range ensures that all air lumes that try to get close to the core would suffer, not to mention the splash damage of the Anti-air 's projectiles.
 * The Scatter lasers & the Cannons as other alternatives are still options, particularly if assisted with a Range spire and not so much vs lots of flying lumes. While the Scatter laser can be a pretty effective alternative of the Anti-air in Sanctum 1, in Sanctum 2 things go different.
 * The Anti-air can find use in most (24 out of the 32) maps of the game, except the ones from Facility and Brightholme, since in the 8 maps of these 2 regions there are no flying enemies.
 * The Anti-air can find good use in all game modes, but it is dependent on the map and mode whether it's worth taking it. While in many maps this tower would do decent job, in a part of the maps it's either clearly not needed, or would find very low use, which kinda' excludes it if the Hardcore feat is active. However, in Survival even in maps with less need of this tower it can be a good plus.
 * Amp spire correlations
 * A level 1 Amp adds same amount of damage as overcharging an Anti-Air to more than 3693 damage and makes for a bigger damage gain if being put before the overcharge.
 * A level 2 Amp adds the same amount of dmg as overcharging an Anti-Air to more than 4623 damage and adding such Amp before further overcharging makes for a bigger damage gain.
 * A lvl 3 Amp adds the same amount of dmg as overcharging an Anti-Air to above 6250 damage and adding such Amp before further overcharging makes for a bigger damage gain.
 * Overcharging the Amp adds the same amount of dmg as overcharging an AA to above 20000 dmg and from then on, max damage gain can be reached by putting equal amounts of resources between them.
 * These correlations are valid for the damage value, reached only via overcharging, without Tinkerer, Engineer, Core-tower synergy or already existing Amp spire. If any of these buffs is in action, it is needed to calculate the damage, gained only by overcharging (or to remove the buffs) to see the real efficiency stats. These 4 mentioned buffs stack additively with each other.
 * The fire rate of the tower in-game is converted into shots per second this way: One in-game speed unit is 1/60 shots per second and therefore come the calculations:
 * The level 1 & 2 Anti-air has 40/60 ~ 0,67 shots per second (= 40 shots per minute = 1 shot per 1,5 seconds), which is 4x times the fire rate of the level 2 & 3 Rocket towers;
 * The level 3 Anti-air has 48/60 = 0,8 shots per second (= 1 shot per 1,25 seconds = 48 shots per minute), which is almost half the fire rate of the Makeshift cannons.