Gameplay presentation – Mutations

When we are asked what our game is about, we simply put it as “Lemmings with zombies”… Thought that it’s not that simple. Sure, you do not control your zombies directly. Of course, they are stupid enough to walk straight in a pit without a second thought and you even give them orders in a similar way.

But contrary to Lemmings, you do not just take a brainless army of flesh eating monsters for a walk. You get out there, you slaughter some helpless humans along the way, and you bring chaos and desperation to the World!

On a less psychotic note, and while we do not hide our inspiration, we do not wish to make just a “Lemmings with zombies”. If it were true, we would have zombies taking parachute lessons, mining with pickaxes and building bridges. Not very inspired… Hence, the concept of mutation that fits more into the – expected – experience of a zombie outbreak. It’s a common knowledge, zombies are stupid and so mutations are the primary way to interact with the game. Without them your zombies do very little: they walk around, smash through doors and attack whatever taste like meat. Thus, using mutations will let you steer them in the right direction, allow them to withstand more damage, move faster, overtake obstacles and so on.

This first article will – you probably guessed – focus on mutations, how they are now, how they were before and what we are trying to accomplish with them.

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Once upon a time

The early versions featured a very simple implementation with few actions – block, run, explode – that provided very little interactions and was kind of boring. The addition of more mutations – climber, tank & screamer – helped in that regard but not enough to have a compelling gameplay. Therefore, we’ve decided to intensify the action side of the game without losing its puzzle component. One aspect that emerged was that we could categorize mutations into 2 distinct categories:

• On one side, we have single time-limited actions so you can make zombie explode or scream for few seconds, or jump.
• On the other hand, we have changes in behaviors and capacities that last until death. For instance, a tank does not react like a normal zombie but also have more abilities.

Combo!

From that point, it took us some time to come up with the idea of mixing them together. The idea is simple, any action can be applied to a zombie, whether it’s a normal or a mutated one. Each action has different results depending on the targeted zombie, if he’s mutated, it will be different. For instance, a tank exploding will have a greater area of effect but will take more time to trigger.

At the moment, we have 6 mutations implemented, not all of them can be mixed together yet.

Behavior mutations

The climber: He’s like Spiderman, but without a brain to make some cool web-shooting device. So he can only climb walls. But thanks to its claws, climbing is not his only advantage; he’s also slightly faster and makes more damage than a standard zombie.

The blocker: As our first mutation ever made, the blocker was originally a carbon copy of its lemming’s counterpart – which just act like a wall. It worked well but it was frustrating to block from all direction. So, we later changed his behavior to select a direction other zombies will follow. The blocker acts more like a dead traffic controller.

 The tank: A devastating, hungry and violent monster, he’s like Hulk without a brain, huh… Well, there is not much to say about him, he’s strong and resistant and he can break some walls if he have to. Ideal to confront heavily armed forces, armored vehicles or to open paths.

Action mutations

The Screamer: With his lovely voice, he’s capable of completely paralyzing his prey. If you remember the ReDead in Zelda: Ocarina of Time, you get the idea! He’s particularly useful against too powerful group of human, paralyzing them allows you to get closer without getting hit.

The Runner: He is faster and do not get stopped when hit by bullets. He can also avoid some traps and is harder to hit.

 

The Boomer: He can explode and by doing so can break stuff and devastate a human group. He’s useful when a group of human is cowardly hiding behind walls. Well, they are not that safe when he’s around. Note that their names are not final, they will most likely change once we find some inspiration!

Contamination

Contamination is a special mutation that is not used on zombies but on humans. It allows us to have different types of levels, either by using spawners to create zombies or by contaminating one or more humans to begin a level. A mix of spawners and contamination is also possible and brings some cool situations as well. You can, for instance, use the horde to push from one side and contaminate your foes behind the enemy line!

 Usage

Using mutations does not come for free, otherwise it would be too easy and boring to use. Our first implementation was really naïve and consisted of a predefined number of mutations useable for each type of mutation. Obviously, that did not work so well because there was no way to regain specific mutations in a clear and simple way for the player.

Therefore, we modified our system to use a classic gauge instead – currently referred as DNA. Each mutation have predefined cost and using a mutation drains your DNA until you run dry. This approach is more interesting in the sense that we can play with the DNA gauge in game. For instance, we are currently giving back DNA each time a zombie kill a human.

 We are currently considering some mechanics we think could be engaging for gaining DNA:

• Sacrificing zombies: Useful when you have many zombies left but not enough DNA to use the mutations you need. This is good way to reduce frustration in this case, and we can use this in our level design to a force the player to sacrifice.
• Increase maximum DNA: At this time, each level can be set with a maximum and a current DNA: you can start with 10 DNA with a maximum of 20. You can then use mechanics to get more until your reach the quota of 20. But it could be possible to increase your maximum quota to unlock some mutations.

• Eating fresh meat: We do not know how it will be integrated, but it’s a feature we really love. Zombies are not complete unless they can feed on humans so we will try hard to make it happen.
• Collectable items: Collecting is relatively standard in games… so why not use it. It’s a clever way to hint for paths and can force the player to perform specific actions to get them.

 

To conclude this first article, keep in mind that even implemented features could be scrapped if we feel they are not fun or simply suck.