Hi, thanks for reaching out! I'll help you now. For your information, if you want/need better or direct contact with me, you can join our discord server and ping me over there too.

Regarding the error:

Can you please provide a little bit more information? What exactly you did and how this message appeared? You created a new project? What is the step-by-step? 

But in advance, this seems like an error message regarding an asset name with invalid characters in it, so you can simply edit the asset and remove this character (right click the asset and rename it). They are invalid because some characters are not allowed for the operation system to be used as file names. So Cave cannot save them properly.

It is very active in development! Itch doesn't show it because the engine downloads are in our website, so the URL doesn't change for itch. But the last release was November 13, 2025.

Due to the amount of new users getting the engine right now, the server is having a hard time catching up. Please DM me in our website: https://uniday.studio/user/UnidayStudio and I'll manually confirm your purchase for you.

Create an account to the website using the same email you have on itch here: https://uniday.studio/cave/onboarding and then, once logged, you should be able to download the engine here: https://uniday.studio/cave/download

This is necessary because our server will build a new Cave Engine specific for you. :)

Cave is meant for 3D Game Development, once your game is ready, in a matter of seconds, with a single click, you can export it to a standalone executable (Linux and Windows) and ship it. Our latest steam game, Crow, for example, was made in Cave.

Hi, thank you for the interest in question! I'm not really sure if I got your question. Cave Engine is a Windows and Linux game engine and it allows you to natively (using the engine) build Windows/Linux games/apps. You can use other python libraries in it too. 

Hi, it doesn't take a while, our website automatically connects to itch to make sure your download is ready. But your account at uniday studio must be using the same email address you used in your purchase (here on itch), otherwise it won't recognize you. If you want me to double verify that for you, please DM me at our website (my profile: https://uniday.studio/user/UnidayStudio) OR send me an email at guilherme@unidaystudio.com.br with the email you used in your purchase OR ping me on our discord server and I'll be happy to help you. Which option you find more comfortable with. 

Thank you for choosing Cave and I apologize for the inconvenience in advance. 

thanks!

😅

Glad to know you found the problem. If you need anything else, let me know!

Hi! I'll help you figure all that out! Does your graphic card/machine support OpenGL 4.3+?

If possible and you want, please ping me on our discord server, that way I can answer to you more quickly and help you figure out what is wrong. 

Now do it in Blender Game Engine. :D

Thank you! No, I've made it using pygame.

Yes! By buying it right now, you'll be guaranteed to get all 1.x.x updates, meaning that you won't have to worry about that for many years to come.

As a reminder, after 1.9.9 it's not necessarily 2.0, it follows itch's version control convention: major.minor.patch, so something like 1.999999999999999.999999999999999 is completely possible. 😅

Hi, what problems are you having? I'll happily help you with them! If you can, ping me on our discord server and let me know, so I can instantly help you: https://bit.ly/discord-uniday-us 

Hey, just letting you know that I've fixed it and updated for version 1.0.3 (already available). Thank you for the report.

Hi, thank you for the report! I'm already working on a fix for it. If you want, you can join our discord server for further help. 

Defintely!

Not yet, and the main reason is that we don’t currently have the necessary VR hardware in the studio for proper development and testing.

That said, if interest in VR continues to grow, we may consider adding support in the future. For now, our focus is on PC (fully supported) and Web (currently in development).

Hi, thanks for your interest in Cave! I really appreciate it.

We previously had a free version for a long time, but after careful evaluation, we found that maintaining it was not sustainable for us—both technically and financially. It also significantly impacted our ability to provide quality support and continue improving the engine.

Because of this, we’ve decided to focus entirely on the paid version, and we don’t have plans to release a free/demo/trial edition. That said, I understand that many of you would like to try Cave before purchasing, so we’re working on providing as much in-depth content as possible on our YouTube channel to give you a clear look at what the engine offers.

Hi, thank you for the interest in the engine. The period where it was free was a very good experiment to see that it is very hard to maintain the engine that way. So the future of Cave was either get completely closed (meaning that only us at Uniday Studio would be able to use it and no one else) OR have this small price that would allow us to alocate time and resources here in the studio to handle the public version. 

In the end, that was the right choice. The results were VERY positive and the engine is already seeing the results of it with new features, quality of life improvements and more. Community is growing nicely also, with lots of cool games and projects being developed in it.

Once again, thank you for being around!

Hi! Cave no longer have a free version available. If you had an early version of the engine that was free downloaded in your machine, you can still keep using it, as the license permits it. But all download links for those old versions are now offline and won't be made available again. Thank you for the interest in Cave!

Thank you! Yes I'm working on ways to showcase the engine more, specially with games like this that were made using it. I've made a video about this particular game two months ago, but it didn't get enough traction on YouTube, unfortunately.

it supports any card with OpenGL 4.3+ support, which an RTX 3070 definitely does (and probably any card released over the past 12 years).

Hey @ObelixSoftware! Thank you for purchasing cave. This error seems to be related to video drivers and/or v-sync. What is your graphic card? The most straight forward fix to it is to update your graphics drivers. If they're already seem to be up to date, I would ask you to try a different driver other than the one currently installed. If you need fast help, consider contacting me directly on Discord also.

Hello, everyone!

 I have some news regarding the first Cave Jam. Since around 80% of the current user base is pretty new to the engine (less than two weeks) and also that less than half of y'all have previous experience with game dev in general (according to a research I ran), I decided to extend the deadline for the jam to incentive y'all to try to finish your games!  

Even if it's a small game, I believe that it will be a great step for YOU and also for the Engine (which of course benefits you).

New Deadline:

So there is still plenty of time to finish: It will be live until January 20th, 17h BRT (UTC -3) (Brazil), 12h PST (UTC -8) (California), 20h GMT (UTC +0) (London). Let me know if you need anything!

Yes. :D

Hey everyone! Since we are close to our first Cave Engine Jam, I'll be hosting a JAM SALE with 20% OFF until the event ends! 

So if you didn't get the chance to acquire the engine yet, this is the perfect timing for you! 

You can Check the JAM SALE here:

[Get Cave Engine with 20% off]

Verdade! Valeeeu!

Yes. In my case, it was amazing, but that's also due to the fact that I'm also the developer behind the engine itself. The latest version available for public download is very outdated already, I'm working on to release the current one we are using here at the studio (and that I used for this game as well) + a lot of documentation so everyone will be able to understand and use it. Stay tuned! :)

Hi! I made this game for the Ludum Dare 55 using Cave Engine. If you also participated, consider visiting my LD page here: https://ldjam.com/events/ludum-dare/55/sandtown

Thanks!

This is a PILOT for the MMORPG Game Jam, so as everyone already expected, I'll be experimenting with the rules and options a bit. So I would like to ask: 

Should I extend the Jam deadline?

I was thinking about a week (7 days) instead of 3 days. What do y'all think?

What I don't think it's cool is if we keep the 3 days deadline, but no one manages to finish in time (meaning that we should've extended it). So let me know how y'all projects are going and if I should keep it 3 days, change or to 7 OR something in the middle.

Welcome to the Jam!! If you want, you can team up with someone from my discord as well: [Join it here]

Oh... and some extra that I almost forgot about:

About the Scope of the MMO:

Some people asked me about this: 

"What should it have to be considered a valid MMORPG?"

And, well, for the sake of this JAM, not much, honestly. I think that the ultimate goal is to make something that we can have some fun with each other playing online, so if you manage to make an online world where people can join and walk around, see each other and interact in some way with them (or the world), like attacking or something, then it's a valid Game.

You don't need to create a fancy advanced RPG or combat system for this jam.. 

(I mean... you can, if you want... perhaps this should ne an Optional "HARDCORE" rule? Let me know!)

But keep it simple in a way that you can finish it in time, ok? 😄

Hello, everyone!

Since this jam is very hard by default, I decided to make a small Guide to help you get started with it and also recommend a bunch of cool technologies and tips and tricks to help you finish your MMORPG in 3 days. Reply this post if you feel like I miss something and feel free to suggest new recommendations for me to include in it in the comments.

About the Rules...

The first thing I'd like to point out is about the Jam Rules:

Tough ones, right?

Well... not really!

What you may have not realized yet is that the ultimate goal of the "hardest jam in the world" is to allow you to ultimate challenge yourself to your own limits, yet still doing something in common with the other participants. But this also means that every participant have different limits and may find some of the rules "impossible" or "easy". That's why they have a bit "OPTIONAL" bellow them. You can pick the best combination of rules that fits your current knowledge extent, and that's totally fine. 😊

What really matters is that you try, push yourself to the limits, and finish the damn game!

So if you want to do all the rules by their 100%, then go for it... but if you want to do only half of them, you're free to pick this setup too.

With that said, let me give you some IMPORTANT tips:

Creating your own "Engine"

One of the OPTIONAL rules for the jam is to use your own Game Engine or technology to make the game. Some people misunderstand this rule a bit, so I'd like to clarify two things:

• #1: You DON'T NEED to make the Engine DURING the event!

I found that people that does NOT know how to make a game engine will probably not have a great time figuring it out DURING the jam (I don't recommend it if you don't know what you're doing, and ALSO, check the SECOND misunderstanding if that's your case) and the ones that DOES KNOW how to make an engine, will probably already have one or at least a bunch of useful code in the developments, so if that's you, you might as well use your tech during the jam. It's fine!

• #2: You DON'T NEED a GAME ENGINE to make a GAME!

This misunderstanding is very common. When I say this "your engine only" rule, people often think that they need to create their own Unity or Unreal for the jam. That's not true. You can simply just make the game by itself, with "no engine", and write your own rendering/physics procedures for it (and yes, you can use Libraries). So if you're new to this "game engine" thing, this is the path I recommend.

Hosting your MMO Server

You'll have to host it somewhere in the internet and the best way to do that is by using a VPS machine with Linux (or something, but Linux is usually cheaper to find - and better - than Windows Servers, keep that in mind). If you never used a VPS before or don't even know what it means, it might be a good idea to check this part before the jam starts and even try to run a program in it, open an UDP or TCP port and so on. So I'll leave this Google Article about what is a VPS here.

But the most important aspect is that I recommend you to choice the VPS you'll be using for the jam and set it up beforehand, since it could be a timely task if you have zero experience with it. VPS are usually not free, but they use to be cheap, like ~$5 a month, depending on the settings. The one I personally use is DigitalOcean, with pricing starting at $4/mo. 

There are plenty of "free tiers" in other providers, such as AWS, Google Cloud and Oracle Cloud. This GitHub Page here have an extensive list of all of them and a comparison of the free tiers. If you go with a free one, JUST BE AWARE that some of them requires you to insert your credit card info AND if you overflow the free tier limits, it will automatically charge you. So make sure you are monitoring the rates to not end up with a thousand dollar bill. :P

Be Aware that Custom TECH may be good...

In an MMO, a lot of the fancy stuff happens in the server side. And it may not be very easy to run "Unity" or something like that in such a limited environment like a cheap VPS... 

So what you'll probably want to do is to write the server side yourself, with the minimal amount of boilerplate code possible. And for that, having your own Technologies (Game Engine, lib, etc) may be a facilitator. Physics, math and so on could become a bit easier to manage if you do it like that. It's not a rule, but it is important to think about it before and plan ahead!

Library Recommendations

If you decide to make your own tech to create the game, or even if you're not, you will still need some custom code for the server side. So I'll be recommending some libraries for various tasks that I find good. All the libs, if not said upfront, are for C/C++, but most of them have a lot of bindings to different languages, so it's worth having a look.

• Enet (for Networking): http://enet.bespin.org/
• Glm (for Math): https://github.com/g-truc/glm

To handle the main Engine/Client aspects, such as rendering, window and event handling, audio and so on, we have those two amazing libraries:

• Gunslinger: https://github.com/MrFrenik/gunslinger - This one is nice!
• Raylib: https://www.raylib.com/
• Panda3D (for Python): https://www.panda3d.org/ - I've never used this one, but people like it

For 3D Physics, we have those two that are amazing. Be aware that it may or may not be overkill to run then on a simple MMO server with simple collisions. But here you go:

• Bullet Physics: https://github.com/bulletphysics/bullet3
• Jolt Physics: https://github.com/jrouwe/JoltPhysics

And if you decided to completely ignore the "It must be 3D" rule, here is some 2D goodies for you:

• Box2D: https://box2d.org/
• PyGame (for Python): https://www.pygame.org/docs/ - This one is nice!

Free Assets Recommendations

Well... what about the "No PREMADE ASSETS" rule? 

As I said, you may want to follow it... or just to completely ignore it in favor of finishing the game. If that's the case, I  only recommend two amazing free assets sources (other than itch.io itself and OpenGameArt):

• https://quaternius.com/ - (they are all Free and CC0 - Public Domain!)
• https://www.kenney.nl/ - (they are all Free and CC0 - Public Domain!)

That's it!

Have a great jam and enjoy it!

Yes! We have an official discord for the Engine:

[Click here to Join!]

thanks!

I made this a while ago and just realized that I forgot to mark the post as published on itch.io! My bad! :P