How Vampire Survivors Made Me Rethink The Concept of the "Core Gameplay Loop"
By Scott "Splinter of Chaos" Prager
This blog post is dual-posted on Scott's personal blog. The views an opinions expressed herein are their own's and not representative of the company as a whole. Original post: https://yapb-soc.blogspot.com/2022/07/how-vampire-survivors-made-me-rethink.html
I first saw Vampire Survivor as demoed on Northernlion’s youtube channel and it struck me as “just another game”. The gameplay looked simplistic, the art looked rough, and the concept didn’t seem like a very big innovation. I didn’t really look at it with any seriousness until I saw “20 Minutes Till Dawn” and “Spirit Hunters: Infinite Horde”. That’s when it occurred to me: this is kinda a big deal. Vampire Survivors only hit the internet in late 2021 and already it has many clones, often by relatively new studios, sometimes even veteran studios. These studios either decided that this should be a trend and would be so big that it was worth the months of development to try and ship a competitor, or were themselves so infatuated with Survivors’ concept that they needed to try their own ideas.
Point is, this game is a pretty big deal and I don’t think I’m alone in having initially thought this game didn’t look like much. Its core gameplay loop seems hilariously simplistic: kill enemies to get gems to gain experience, level up, and kill more enemies. One could probably describe very well-respected roguelites like Slay the Spire and Rogue Legacy the same way, but I think many would also point out the boss battles, the lore, and how skill-based those games feel. I want to put a pin in the skill part for now and focus on bosses and lore, which are not necessarily a part of the core loop, but I think are key to understanding Vampire Survivors.
It took me quite a while to understand Vampire Survivors on a level deeper than “some people find ‘bullet heaven’ fun” and that led me to question the utility of thinking of core gameplay loops as simple loops.
I usually hear this discussed in terms of micro and macro; micro being what you’re doing now and macro being what will happen soon. For Vampire Survivors, the micro would be the loop I described above, but the macro is a bit more interesting. When you go into a stage, you might have a goal such as “explore a specific part of the map,” or “collect gold,” the meta-progression resource. You might be completing a challenge which will unlock some new content upon completion, some of which are to “evolve” a weapon (upgrade a weapon to the max level while having a specific item in your inventory). To accomplish this goal, you might have a specific build in mind. But just having goals or higher level objectives doesn’t seem like enough for a game to be special. What’s the secret? It takes a moment to explain…
At the start of the game, you have just one weapon and every time you level up, you might gain an additional weapon which changes your build, get an item which enhances the build, or upgrade a weapon which scales your damage. As time goes on, waves get stronger and you need these upgrades in order to match your damage output to keep up with the enemy spawn rate which is also increasing over time, or at least be able to outrun them. On a good run, at some point, you will have outpaced the spawn rate and just mow enemies down–what is often referred to as “bullet heaven”, and from then on the player is unlikely to lose until the timer expires and the reaper comes out. Even from a very simple mechanical base, Vampire Survivors is able to evoke a number of different emotions in the player at different stages. It creates different feelings across each stage which makes them feel more compelling, less monotonous.
This is what I really missed when I looked at Vampire Survivors before, and what shows me the flaw of viewing a core gameplay loop as just a loop. You could look at it as a spiral, too. As the game continues, the loop of kill -> collect -> level -> kill changes and recontextualizes over time. At first, you are weak, but enemies are infrequent, collecting EXP is slow. As you gain another weapon, your ability to chase down enemies increases and you can gain EXP a little faster. Eventually the enemies start to come in faster than the player can kill them and there’s this push and pull as you need to run away to not get killed, but you also need to circle around to collect the EXP they drop. After a few level ups, you get a weapon evolved and become overpowered and nothing can touch you. Leveling up goes from just trying to gather a few extra weapons so you don’t get outpaced to trying to optimize the damage output as quickly as possible and trying to set up evolutions, to maximizing your weapons, to finalizing the build, and finally just cleaning up whatever upgrades are left to collect. Every part of the loop changes as you progress through the game and so after going a few cycles through it, you find yourself not actually in the same place as where you started.
I’ll refer to this as the “core gameplay spiral”; the way that iterations around a core gameplay loop alters the dynamics as the game changes over time or just in general progresses. By breaking the ideas of the core loop, progression systems, and time apart, it becomes harder to understand how they relate to each other and especially treating the core gameplay loop as static discourages understanding how it evolves over time. The core actions you’re doing never change, but how they feel does change, as do the dynamics they create. I further posit that games will probably, generally, be more interesting when their core loop is not static, and this extends to meta-progression, too.
The one backtrack I have to make is that the “core gameplay loop” is typically only a mechanics-deep analysis that does not consider extraneous elements like dynamics or progression. So maybe saying “core spiral” isn’t a great name because it suggests that the spiral is just the core loop unraveled. It is not, they are separate concepts for different layers of abstraction.
Earlier, I did briefly mention that I think one aspect of Vampire Survivors that might lead some to disregard it is that it appears to have a low skill floor; that is the minimum amount of skill required to be proficient at a game. Even the skill ceiling doesn't seem particularly high. But I hope it’s clear that this doesn’t actually matter very much since the progression of the core gameplay loop more than makes up for this. Both “Spirit Hunters: Infinite Horde” and “20 Minutes Till Dawn” add much more skill-based elements with their faster gameplay and “20 Minutes” even requiring that you manually fire your gun, yet I feel they just miss the point. Their core loops are static in comparison to Vampire Survivors. In “Spirit Hunters”, the stats of weapons can change, but the weapons themselves change very little, they don’t evolve, and only occasional pets will give global bufs to your hero. Every round has largely the same goal: collect gems (the meta-progression currency) to unlock more on the web (a very large skill tree, essentially). “20 Minutes” has more characters and weapons to unlock and you can freely mix and match them, but there is less to unlock, it all unlocks fairly quickly; and since you manually control the weapon and it always fires bullets from the same point, there are just less dramatic changes to the core loop throughout each run. They are both good games and some may prefer one or both over Vampire Survivors, but in my opinion they aren’t quite at the same level.
The insight I have gained from this analysis is that when I’m thinking about my own designs, I want to think primarily about this core gameplay spiral. One with a simple loop at its base that is expanded as the player spends time in the game and creates different dynamics at different points along the spiral. And what I want to avoid is thinking of the gameplay loop, micros and macros, and progression systems as parallel entities. As a practical example, while working on a deckbuilder roguelite, I asked myself “why does picking the second card feel different from picking the first?” and after doing so, I’d realized it did not. I had the progression systems, the loops, and all the features I thought made a good game, but I didn’t have decisions properly compounding on each other and thinking about how the loop should change over time pushed me to make some significant changes to my mechanics, hopefully for the better. And so I hope that this analysis might similarly help others see their own projects in a different way, ask the right questions, and find better solutions.