Immortal Defense

Immortal Defense
Immortal Defense Cover
Platforms Windows
Genre Transcendent tower defense
Buy from Developer

Our second entry in this indie game month is a tower defense game by Studio Eres entitled Immortal Defense. I use the phrase "tower defense" lightly here, as while marketed as such, (Immortal Defense – a Tower Defense game), the creators only borrowed the genre basics and strived for much more than tower defense game #481.

History of defense

In case you aren't familiar with tower defense, it is a strategy gametype where the player is thrown into a fairly large, relatively open area with start and end points. As a level begins, waves of mindless enemies trickle from the start point and make their way to the exit. It is your job to place towers in strategic locations to hold off this onslaught. Resources and available towers are limited at the start, but increase as you kill enemies and as time progresses. Tower types are somewhat varied but usually have characteristics such as single shot vs multishot vs cone vs aoe, perhaps the ability to slow/freeze, and varying ranges from poking distance to full screen. The roots behind the genre have been around for a while but seems to have really taken off over the lifespan of Warcraft III. The mod creation tool led itself perfectly to creating tower defense games and many people were soon spending hours blowing up hordes of mindless drones. Following the huge success of these games, tower defense soon spread beyond mods to more easily accessible flash games and even standalones such as Defense Grid (on XBLA/Steam), and that's where we are now.


Immortal Defense, while admitting a tower defense engine, tries to be as unique as it can within that mold. Gone are any grids on which to place your towers. Thus also gone is the concept of "mazing" your enemies around the board to get optimal travel distances and attack time. Immortal Defense gives you a path, a start and an end.

Immortal Defense Path

Enemies travel along the path and it is up to tower placement to stop them before a given number reach the end. Resources (cache) are gained by destroying enemies and your performance throughout the level impacts how many carry over to the next level. Your ending resources are modified as a percent by how many "hits" you have left, along with a bonus depending on your final cache. This creates a strong motivation to be efficient yet careful to prevent enemies from passing through, as available cache can quickly boom or implode, depending on whether you're smart or careless. Luckily, if you do manage to pass a level with a cache disaster, you can redo it at any time (on any difficulty) to fix the cache for the next.

The game has six main campaigns with 15 levels each. Resources will carry over through 1-14, with each 15th as an endless mode to test your new skills and burn your resources in an attempt to last as long as possible. Your resources at the start of the next campaign are slightly modified by how long you lasted in the previous endless mode, but it still more or less stops the inflation and starts you over from scratch.

The game

The game itself is highly tied to its story, which is quite impressive for a tower defense game and manages to do a lot in a short time as long as the player is willing to step back and put on their philosophy hats (I'd like to know what a philosophy hat looks like...). At first glance, you are put into the shoes of a planetary defender codenamed K. For some reason, Dukis, your planet, is under attack from an alien race called Bavakh. Dukis is completely outmatched and all signs point to slaughter. However, there is one last technological hope. Everyday life is lived on the normal space, the standard dimension. Above that is hyperspace, the dimension on which light-speed travel is based. And further above that is pathspace, a dimension on which all beings merely travel along on a line. See how things are tying together now? Dukis is able to send you up to pathspace as its only pathspace defender and as its only chance to defend itself against the traveling Bavakh fleet before it reaches the planet. Along the way, you come in contact with various individuals, whether they be pathspace defenders or space architects or just contacts from your home on Dukis. While the game occasionally implies that you CAN communicate to others, it only shows you receiving messages while making a shift to become more or less a tireless pathspace fighter above all other duties. This type of writing makes it difficult to get into the story at first, but it gets much easier once things become more clear. These themes repeat themselves throughout and purposely instill a feeling of isolation as K.

Immortal Defense Conversation

The towers themselves are not just towers in this world. Towers are 'points,' with each corresponding to an emotion. They are as follows:

  • Fear: Fear is a cornerstone of any defense, why protect if you don't fear a loss? Rapidly shoots the highest defense enemies in range to stun (more of a slow tbh). Also lowers defense and prevents some special abilities.
  • Courage: Courage arises to counter fear, extending and invigorating defense. Basic attack model with straight shots; pierces through enemies to hit ones behind, can wrap the screen.
  • Ortho: Reason and logic must take over to make a defense more robust. Can only shoot at right angles plus or minus ~10 degrees, has splash damage, very cheap to build.
  • Cut: Once logic and instinct combine, a powerful will is necessary to obliterate anything in its path. Spreads mines in its radius, exploding with strong splash damage on hit.
  • Limited: Part of your will probes beyond the limits of normal space to path space. Periodically rapid fires slow-moving projectiles which gravitate to the least damaged enemy in range.
  • Love: Love develops when a being becomes conscious and allows a defense to grow beyond itself. Boosts the damage and range of points with a cumulative effect.
  • Circuit: Love represents awareness of support while circuit represents growing knowledge that without connections, no defense is possible. Combines with other circuits to create lines which hurt enemies upon touch.
  • Pride: Pride develops once a defense is in place with confidence to defend a path. Fires homing javelins, power increases with each kill, capable of criticals.
  • Strategist: Once pride is developed, strategy is able to maintain that ruthlessness but sees outside of the box to search for weaknesses. Fires at cursor targets, does a flat percent to enemy hp while lowering defense; also redirects nearby attacks to its target.
  • Turning: Rational defense can be broken by opposition's rational force; turning point resists reason and is not afraid of experimentation to succeed. Flies around and fires erratically, ignores defense and damages maximum hp.
  • Danmaku: Large, expensive point with varying attack methods depending on its level. (The game text does not know what to make of the Danmaku but it is apparently an alternate name of the bullet hell genre of shoot-em-ups)

Each point can be upgraded to level 7, with higher levels offering vastly improved and sometimes even different forms of attack. For example, several level 7 points have infinite range and may have their attacks changed to say, attack the cursor's target instead of firing at random enemies.

Speaking of the cursor, it is the other significant aspect of the gameplay in Immortal Defense, and an interactive one that you rarely see in tower defense. The primary attack of the cursor is a short-range continuous rapid shot which automatically turn and attacks nearby enemies. The secondary attack is a charge, initiated by pressing the right mouse button and released by pressing right or left mouse. It can charge up to four times in later levels, for progressively effective and explosive area of effect attacks. The charge also interacts with points in various ways; the explosion can direct nearby Danmaku and Limited attacks as well as push Cut mines into enemies while active. Love points affect the cursor's damage as well and Circuits create a circuit with the cursor if it's within range. Overall, the gameplay is respectably deeper than most other tower defense games. Most can be played by setting towers and fast-forwarding through most of the game, but Immortal Defense's cursor attacks and interactions are essential, making it a much more engaging and rewarding experience.

Immortal Defense Cursor


The game's presentation is also very unique. At first sight, it takes a basic, almost wireframe approach to graphics. The enemies are simply sprites surrounded in extremely basic polygons. The cursor is more or less a green arrow, the path is a shiny line and the tower points are plainly colored circular objects displaying their symbol. We also have tiled backgrounds for ambiance and a barebones (yet effective) UI at the bottom. Points are placed by either dragging from the lower bar to the play field or by pressing the corresponding number on the keyboard and holding/releasing left mouse for a moment to place. Upgrades are performed by mouse over + hold/release. Points can be sold by either clicking on the point and pressing the sell button or by mouse over + S. Pressing P will pause, holding Space will show upgrade costs and Ctrl will display kill counts for each point.

Behind this seemingly innocuous exterior lies a beast of graphical effects, shaders and filters that are more than willing to burn your retinas if you would so allow it. Mines explode in flashes of light, shots continually wrap the screen with massive trails and projectiles follow your commands in screen-wide charge attacks. I started the game turning the graphics slider to 10 but realized by the end of the first campaign that the increased light show made it near impossible to see what was happening. This made it very difficult to react as the levels got busier, so it was soon lowered to the default 40 for playability purposes. 40 is still a tremendous light show but more importantly quite playable for someone new to the game. The graphics ramp themselves up progressively through the game, right up to the spectacular finale. I was a bit disappointed by overall game engine performance though. It's held to 32 frames per second for some reason, perhaps for stability or because the developers liked the feel at that level. But judging from similar games graphically, it would have been significantly more playable and much more vibrant if allowed to go higher. Also the game would not stay at 32 fps even on a strong processor. At times of particular craziness, it would dip to the mid 20s. Checking system utilization, I found that the game was purely single-threaded, which would lead to performance dips on almost all systems considering just how processor intensive it is. However, I can't particularly blame the developers for this as they have limited tools and knowledge/time to work with (it is an indie game after all). I'd also like to note that screenshots don't do this game's visuals justice as the effects are much more vibrant in motion.

Immortal Defense Colors

Rounding out the presentation and technical aspects of the game is the sound. The sound effects seem like more or less standard .wavs you could find lying around a computer. They do their job, aren't overly intrusive to overwhelm the visuals but still make their presence known when needed, particularly the shield/shattering noises and the occasional screen-clear chain. Music tracks are somewhat varied, but most stages have generally appropriate orchestral works, which can both emphasize the isolation and calm of path space as well as increase tension during stress and heavy fighting.

Final Thoughts

All in all, I very much enjoyed the game and would recommend you try the lengthy demo at the least. If you've played tower defense before, you'll fit right in to the starting gameplay. If you haven't, you could discover it here. At 6x15 levels, it has about 10-15 hours of gameplay in the main campaign, with several more/a new dimension unlockable once you clear each level without letting any ships go through. It has a full range of difficulties for all players, with a good default starting level (I did have to lower it to beat a couple stages at the end for time reasons :P). A level editor is also included.

It's difficult to relate this game to others but it is tower defense at heart, with similarities to the deceptively basic visuals of Rez, maddening projectile chaos of Bangai-O, low-key sweeping sound of Gigawing 2 and a deep, shifting story that can stay with like Braid.

Here is a video of an early stage to demonstrate gameplay and presentation: