Radiant Defense Strategy Guide

The concepts of strategy and tactics elude our alien enemies. They are driven by hunger, blind rage and a simple urge to push forward, no matter the cost. Even so, defending humanity against their infinite multitude is an overwhelming task. As mindless as our enemies are, they know no fear, they never retreat and they come without number. May this guide help your cosmic fortress persevere and bestow spectacular punishment upon the unyielding tides of alien monstrosities.

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One of the most important objectives in Radiant Defense is to keep your economy in healthy shape during the entire mission. The income from just the alien kills won’t suffice to buy the vast arsenal necessary to finish the mission with three stars. Efficiency Bonus received at the end of each wave is an essential source of income and it’s exactly +10% of the money you have saved.

Do not overspend! Save as much as you can.

If the aliens die too easily, it might be a warning sign that the money could’ve been saved for later and generate bigger Efficiency Bonus along the way. Saving 500$ to receive the maximum Efficiency Bonus (50$) is no small task, but it’s the one that’s guaranteed to pay off when the push comes to shove.

Keeping your spending at a minimum requires very careful investments into new weapons. Should you buy a new turret or should you rather upgrade the one that you already have? In case there is a new type of threat coming and you’re going to need an entirely different type of weapon then do what the situation calls for. In almost all other cases it is significantly better to upgrade your weapons rather than to buy new ones.

Upgrade your turret instead of building more of the same.

A fully upgraded (Master) weapon is roughly 7x better than its freshly built (Basic) version. The combined cost of all the upgrades adds up to just around 3x the cost of a new turret. When you upgrade the weapon to the max, you get the firepower of seven turrets for the lower cost of just four. Upgrades mean more bang for less buck, literally. Exact numbers are different for each weapon but there’s one rule that applies to them all; the more costly the upgrade, the bigger the increase in firepower and efficiency.

That said, it would be foolish to place all of the responsibility on just a handful of Master turrets. As the waves of enemies get longer and tougher, we’ll need entire batteries of turrets to cover the route from vortex to the Spiral. Too often a single unimportant runner distracts our best turrets, diverting them from the main alien mass, wasting their precious firepower as they rotate around trying to score a hit. Which is why the correct placement and distribution of turrets is vital.

Every turret prefers to acquire targets closest to the turret itself.

A weapon won’t recognize which target is most important to kill at the moment. It will simply shoot at the alien that was closer than the others. Our goal is to protect the Spiral reactor, so it’s a good idea to build a backup force there; when the enemy gets close to the Spiral, these turrets won’t be distracted by anything else. Consider building a sequence of auxiliary killing zones behind your primary kill spot. In case a loose survivor escapes your main force, secondary weapons would make the kill so that your master turrets can remain focused on their important work.

Place the energy weapons (Tesla, Flamer) at the beginning of the route.

Let your energy weapons strip the forceshield bubbles off the aliens. Bombard the bulk of alien mass with your splash weapons (Spray, Cannon, Missile Launcher) to soften them up. Use the precise weapons (Laser, Gauss) last, to finish the remaining survivors without taking any chances of them avoiding a bullet.

Do not limit your setup to just few types of weapons. Variety is the key.

Every weapon in Radiant Defense plays a vital role in successful extermination of the alien threat. Use Tachyon Generator to slow your enemies down. While their movement is restricted, let the Stormguard Tesla work on their forceshields. Tesla-shocked aliens are more susceptible to damage from all other weapons. Blast them with Starcrusher Cannons and Seraphim Missiles, then spray what remains with Biocid to let the lethal mixture of poison and acid get under their armor. Burn anything that regenerates with Typhon Fury Flamer and install Recuperators nearby, to collect double money from all alien kills. When you have enough firepower in place, add Brightmark Searchlight to multiply the efficiency of your entire setup. Ill-fated aliens marked by the Searchlight receive up to 200% more damage. If there’s anything that’s giving you an unexpected trouble, use Proximity Mines or Blades to quickly dispose of the troublemakers.

Place new weapons during the build phase. Upgrade the others during the wave.

In case anything goes wrong, you can always choose to Retry Wave and return to the previous build phase. If you’ve made your upgrades during the wave, choosing to Retry Wave will undo the upgrades, allowing you to spend your resources differently. If you’ve built new weapons that didn’t met your expectations, you can sell them at their full price. Notice that you can sell your weapons without loss only during the same build phase in which you’ve placed them. After they are used, their price drops down to half. However, when you return back to the build phase through the Retry Wave option, you can sell them without any loss.

Slow your enemies to a halt with Tachyon Generators and Psionic Terrorshock.

Usually you won’t need too much of those expensive slowing devices. Modules come free, so you can always try to keep the aliens in your range longer by simple twisting and turning the route. However in some missions like the Mission 4 and Mission 8 you’re essentially left with the predetermined route. In these cases it’s worth to spend more of your money on Tachyon Generators and Psionic Terrorshock so that your other weapons get the crucial time needed for a kill.

For more hints and tactics visit the in-game HELP section. There you’ll find information on different alien types, retrying waves, score system and more.

Walk-through videos by

To see how to finish any particular mission from the start, you can watch excellent Radiant Defense walkthrough videos by


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