The initial presentation adds a really nice touch. It emulates an old operating system with simple rectangular windows and a classic letter-style font, which immediately sets a nostalgic tone. This style smoothly transitions into the main gameplay, where you progress through ten scenarios or stages that must be completed in order. The good thing is that you can always continue later from the last stage you unlocked.
The gameplay belongs to the tower defense genre. In each stage, the goal is to survive all incoming waves before enemies manage to destroy your castle. Every time an enemy reaches the end of the path, where your castle stands, you lose one heart. If you lose all of them, the stage ends. To prevent that from happening, you can place five different types of towers, each with its own firing pattern and purpose. For example, the knight is the most basic and cheapest unit, firing a single arrow at a time. On the other end of the spectrum is the inferno tower, the most expensive option, which launches fireballs that deal splash damage.
Tower placement is limited because you can only build on specific spots marked with squares. At the same time, you are limited by your starting capital, which increases whenever you defeat enemies. That money can then be spent either on filling the remaining tower slots or on upgrading the towers you already placed. Naturally, every upgrade increases the cost of the next one, and each tower can only be upgraded a limited number of times.
Enemies also occasionally drop chests. These provide random rewards such as extra money, temporary damage boosts, or other bonuses. However, opening them involves a bit of a gamble. There is always a chance that the reward lands on a bad outcome, which gives you nothing and even destroys one of your towers. If you do not feel like taking the risk, you can simply leave the chests alone.
The unique mechanic is the crystal system. There are seven types of crystals, including ruby, pearl, and diamond. They have a chance to drop from defeated enemies, but each crystal is tied to specific enemy types or conditions. For instance, sapphire drops from flying units, while topaz can only appear on elite enemies. To make things more interesting, some enemy types only start appearing in the later stages, although by stage four or five you will have access to all possible crystal drops.
Crystals have several different uses. The first is enchanting towers. Each tower can receive one of four enchantments, such as increased damage or improved gold drops, and every tower requires its own specific crystal type for these upgrades. The second use involves spells, which consume crystals when cast. For example, a meteor strike attacks an area of your choice and costs two rubies, while two topazes temporarily increase the amount of gold you earn. After casting a spell, it enters a cooldown period before it can be used again.
What makes crystals particularly interesting is that they carry over across the entire game. Any crystals you do not spend during a run remain available for later stages, so nothing goes to waste. Their most valuable use is in the permanent upgrade system. Upgrades are divided into several categories: individual upgrades for each tower, general upgrades that affect everything, and a set of additional auxiliary upgrades. Through this system, you can also unlock new spells.
Each category contains only a handful of upgrades, and every tower has seven upgrades in total, but they still make a noticeable difference. Tower upgrades typically improve attack power, firing speed, or add special perks. For instance, the magic tower can gain a chance to instantly execute enemies that fall below a certain amount of health, while the knight can unlock a ricochet ability that allows arrows to bounce between enemies. General upgrades affect all towers and include improvements such as increased damage, faster attack speed, greater range, higher critical chance, reduced enemy health, and others.
Although the upgrade system mostly follows a linear path, there are several points where you must choose between two completely different options. For example, the berserker tower can either gain a chance to deal poison damage or receive a boost to attack speed and damage. The upgrade you do not choose becomes locked. However, you can later change your decision by spending a rare crystal. Since stages can be replayed, it is possible to farm crystals if you need them. This is made easier by the auto-wave feature, which allows the game to automatically send waves until the stage is finished or your castle falls.
Grinding mainly works for the more common crystals, which you also receive as rewards for each wave you survive. Rare crystals are a bit more tricky to obtain and mainly come from special challenge waves. These appear after you complete all normal waves and decide to keep playing. At that point, the game begins spawning challenge waves with modifiers such as faster or tougher enemies. Surviving one of these waves rewards you with a rare diamond crystal and a generous amount of money. You can continue fighting for as long as you want, or until your castle finally falls. Since there is no penalty for trying, there is little reason not to push as far as possible.
At the end of the day, the game is fairly short. You can finish everything in about two hours without much difficulty. The basic knight tower can be fully upgraded quite quickly, and a group of them, supported by one or two mage towers, is strong enough to carry you through every stage. And if you add a few extra hearts to your castle, it can withstand the ones that slip through.
