With this weeks sale of Square-Enix games in honor of Chaos Rings release, I thought it fit to review Crystal Defenders for iPad. This is a very fun strategy/tower defense game: hardcore players apply only.

Crystal Defenders has you assume the role of master strategist as you place your units on a map to destroy the oncoming 30 waves of monsters trying to steal your crystals. Before you begin a game, you have to choose which game style you want. There are three to choose from: W1, W2 and W3. W1 is the easiest and simplest. The maps are not difficult and you do not have any power crystals (more on that later). W2 brings in the use of power crystals during gameplay and more challenging levels. W3 is the ultimate challenge. New monsters, units and very challenging maps.

The game revolves around Gil, which is your money/source for everything in the game. You use Gil to place units on the board and to upgrade them. The waves of monsters are cued up on the left of your screen and your units on the right. Before each wave of enemy monster you can place as many units as you would like onscreen till you use all of your Gil. Then, with the tap of the screen the oncoming horde commences towards the level exit and you have to cross your fingers that your units can defend your crystals. The good news; even during a wave you can still place and upgrade your units and if needed pause the action in the middle of a wave. If you become impatient, you can speedup the action 4X so waves complete very quickly.

You have a wide variety of units and monsters. There is the standard solider fanfare as well as archers, mages, thieves, hunters, etc. All of these types of units are necessary as monsters have varying levels of HP, resistance to physical, magical or air attacks and movement.

Once you progress past the W1 levels, the W2 levels give the add strategy of power crystals. There are three crystals in your arsenal: red to increase damage, blue to increase distance and yellow to increase speed. It is imperative to place these crystals next to your most important units to give them an edge. Just like other units, the power crystals can be upgraded, but at a much higher Gil cost than your units. You also have the ability to cast what are called Espers. Espers are creatures that can cast a spell for a wave, like increase all unit damage for that wave; Espers come in really handy.

If you think you have what it takes, then this is the ultimate in Tower Defense games. Three levels of varying difficulty and challenges, deep strategy (it's the only way to win) and creatures and characters from the Final Fantasy universe make this a must have game for the enthusiast.

[$3.99- iTunes Link]