The Reef by jakemchugh1
Welcome to The Reef!
Check out our simulation game of an ecosystem surrounding coral reef. Ecosystems are finely tuned to maintain balanced populations of predators, and prey. Tip one little component out of place and the whole system can collapse! To capture the fragility of real world ecosystems, our game simulates the interactions between two competing animal populations by leveraging real world biology and mathematics to create a simulation of how predators and prey populations interact with each other. It's up to you to keep both the predators and the prey of The Reef Alive!
https://www.youtube.com/watch?v=Xil8-Fc52gs
Cause Collapse or Explosion!
The fate of the animals living in The Reef lies in your hands. Manage and balance the populations of various predator and prey species, by controlling the parameters of the simulation. You have access to four buttons on the lower left of the screen, that control birth rate, death rate, the consumption of prey, and the probability of predators and prey interacting. Control these parameters and watch the ecosystem collapse or the population explode!

Battle Man-Made Disasters
Use your control over the ecosystem to combat the negative effects of man-made disasters. These events range from coral bleaching, to overfishing. Try to combat these events or watch the effects play out in real time.
Let us know what you think
Please try out or game and comment to tell us what you think! Our approach to the theme of "Keep it Alive", was centered on how do you keep two populations alive when those populations can negatively affect each other. Rather than thinking about how to keep a single individual or group alive we thought about how species survive and thrive over time what kind factors influence that. We hope that our game demonstrates how difficult and exciting it can be trying to keep two groups of animals alive simultaneously.
A look at the Math
The equations that drive the simulation are known as The Lotka–Volterra system of equations. This system is comprised of two differential equation that describe the change in a population over time. These equations are linked in such a way that a change in one affects the other! Below are the equations our simulation generates data of off:
Prey: - dx/dt = b * x - h * x * y Predators: - dy/dt = c * h * x * y - d * y
The parameters above are: - b: The prey birth rate - d: The predator death rate - h: The interaction rate between the two populations - c: The conversion rate from prey to predators - x: The number of prey - y: The number of predators
By integrating over these equations with respect to time we can find the population at a given time, like the graph below!

AS you can see the populations of prey and predators "chase" each other over time. As the number of prey increase, there is more food for the predators and thus their population will grow until they deplete the prey population and can no longer support their own population. below is a zoomed in version of the plot above that shows the inflection point where the predator population grows to large and cause the prey population to fall rapidly. (You can see these graphs play out in real time with actual populations in the game!)

What happens when we mess with the parameters, below are some examples of what can happen when things get thrown out of balance. Below is an example where the birth rate of prey was set to zero thus causing the predators to die off suddenly!
And this is an example of what happens when we set the predator death rate to zero, or in english making the predators of the system immortal!

Unstable systems like these can happen due to the simulated disasters we built into the game. Try control the different parameters to combat the collapse !
| Youtube | https://jakemchugh1.itch.io/the-reef |
| Youtube | https://jakemchugh1.itch.io/the-reef |
| Youtube | https://jakemchugh1.itch.io/the-reef |
| Youtube | https://jakemchugh1.itch.io/the-reef |
| Original URL | https://ldjam.com/events/ludum-dare/46/the-reef |
Ratings
| Overall | 1586th | 3.338⭐ | 36🧑⚖️ |
| Fun | 2429th | 2.471⭐ | 36🧑⚖️ |
| Innovation | 167th | 3.956⭐ | 36🧑⚖️ |
| Theme | 367th | 4.071⭐ | 37🧑⚖️ |
| Graphics | 886th | 3.857⭐ | 37🧑⚖️ |
| Audio | 858th | 3.382⭐ | 36🧑⚖️ |
| Humor | 2014th | 1.633⭐ | 32🧑⚖️ |
| Mood | 931th | 3.545⭐ | 35🧑⚖️ |
| Given | 66🗳️ | 36🗨️ |
I think the interaction rate is a bit off, every time I increase it, the ecosystem dies.
Other than that it is a nice simulation (maybe more of a simulation than a game, but that's totally ok!)
There appears to be no way to exit properly (only alt f4). Did I miss it?
(fyi linux executable works)
In terms of gameplay, the UI was a little confusing and so was understanding what was happening. I really hoped to have more minute control or see wider scale changes. I understand that this would be really hard to implement, and I think you did a really good job considering the time restrictions. I missed having more events and more things to do.
All that said, a really innovative game from a classical interpretation of the theme. Loved it.
We originally intended to have a web in browser version, but the graphics that were rendered weren't doing it any justice and didn't best represent the hard work that went into the game, so we elected to remove the in browser version.
I have it on my phone and it runs "swimmingly".
I'm not sure if this is a bug, but when I first got a game over, that text stayed at the top permanently when I restarted the simulation and it was behaving to the parameters I adjusted. In one instance, my reef suffered from coral bleaching and the red game over text indicated that for a split second before reverting to the other text that simply mentioned that my ecosystem had crashed.
I also think the graphics could have benefited from making the predators and prey more distinct. The vibrant colours do make the fish stand out, but some of the predators and prey share the same colours and that made it difficult to tell how I was affecting the ecosystem as I could confuse predator and prey - particularly when they were all grouped together or farther away from the screen. That aside, I was impressed by the amount of details that were added to the reef itself, especially with the variety of seastars. It would have been cool if the seastars also played a role as predators, but I suppose that could be for a different simulation.
Regardless, I'm glad to see an entry that has this specific take on the theme be executed so thoughtfully. It really makes me think. :thinking:
As to the red text, that is a bug and we will have to look into fixing that. We were programming and working on
The predators colors are actually restricted on the color spectrum from blue to green. We didn't want to make them darker colors because we didn't want them viewed as "bad" because predators are necessary for a healthy environment. So we elected to leave them as vibrant colors but restricted as to distinguish. But maybe you are right and we should do something to restrict them to a greater contrast as to distinguish them from the prey.
We also wanted to have a hunting mechanic where the predators actually "hunted" the prey to cull the population to where it was. We had a version implemented but it wasn't working correctly at release and had to cut it for time.
The main menu was going to have a wave shader that showed the surface of the ocean that was working but we ran out of time to implement.
We did want to have more varieties and creatures, such as crabs, clams and octopus but were constricted due to the lack of time.
The environment was going to react to the disasters, as in pollution would change the color of the water, trash would be visible. Coral bleaching was going to drain the color from the coral. Over time if the environment was healthy then more coral would grow.
This took probably 60 out of the 72 hours to make with both of us working. We were programming and then had to build and upload the game with 5 minutes to spare.
I am planning on fixing a few things and posting a post jam version with some of the other features and sounds we wanted to include, so keep an eye out for that. You can follow me on:
https://jakemchugh1.itch.io
I do feel that the simulation is still beautiful and robust given the amount of time we had to work with and am proud.
Out of curiosity, I left the game running without touching any of the bars and the ecosystem thrived for about 5 minutes before I started toying with the bars. I don't know if that is an issue or I'm just very lucky.
The game is extremely relaxing and an excellent take on the theme. So innovative! The concept and science is beyond my intelligence, but even it the most base level the game is just calming and serene. :slight_smile: