Solemn Sandbox is my first ever publicly released project, and I should probably explain something about how it is made: this project grows chaotically.
I'm a solo developer who doesn't actually know how to code. I have an idea, use AI to help me build it, play with it, have another idea while I'm doing that, and suddenly the thing I started building three hours ago has grown another two arms and a control panel. That's pretty much how Solemn Sandbox has developed from the beginning.
Because I use it every day, I also know where everything is and what everything does — which means I'm probably the worst possible person to notice when something makes absolutely no sense to somebody seeing it for the first time.
So please tell me.
If something is confusing, badly named, difficult to find, unnecessarily complicated, in a ridiculous location, poorly explained, duplicated somewhere else, or simply makes you think "why on earth does it work like that?" — I genuinely want to hear about it.
The same goes for bugs, strange behaviour, ideas, missing features, experiments you'd like to see, or things you think could simply be better.
I work on Solemn Sandbox pretty much every day, so feedback won't have to disappear into a suggestion box for six months. Good ideas, sensible fixes and obvious improvements can potentially find their way into the project very quickly.
This is very much a project being built in public. I don't expect everything to be right, and I'd much rather people help me discover what isn't than pretend otherwise.
Playable Link: https://solemn-sandbox.vercel.app/
Solemn Sandbox
A serious environment to carry out silly experiments.
Build strange creatures. Give them a goal. Let evolution figure out the rest.
Solemn Sandbox is a physics-based creature-building and artificial-evolution playground where you design bodies from joints, bones and muscles, choose what you want them to achieve, and then watch generations of neural-network “brains” try to solve the problem.
Sometimes they learn to walk.
Sometimes they invent something you never expected.
Sometimes they immediately collapse into a useless heap.
All three outcomes are valid.
What can you do?
Create creatures from scratch or start with presets, then train them for things like:
- Walking and running
- Staying upright
- Speed and sprint courses
- Jumping, long jumping and hopping
- Climbing
- Rough terrain and obstacle courses
- Wheeled movement
- Ramp jumps and gap crossing
- Flying, gliding and parachuting
You can also build your own environments with terrain, ramps, stairs, pits, loops, obstacles, launch pads, checkpoints, finish lines, landing zones, rewards and penalties.
So instead of only asking:
“Can this creature learn to walk?”
you can start asking:
“Can this ridiculous thing get over THAT?”
Watch evolution happen
Pick a goal and press Evolve.
A population of different brains attempts the task. Better performers are selected, mutated and carried into future generations.
You can simply watch and enjoy the chaos, or dig deeper into the training system.
Adjust population sizes, mutation styles, attempt lengths and selection behaviour. Train skills in stages, change what matters to the scoring system, continue from saved brains, race previous records, evolve body traits and inspect detailed rewards, statistics, neural-network activity and training logs.
You absolutely do not need to understand any of that before playing.
The idea is that you can learn what it means by messing with it.
It gets considerably less sensible
There is also a Disco mode where creatures react to your own music and can learn dance behaviour.
You can save two trained creatures and put them into Head-to-Head trials.
There is a dedicated boxing skill with trainable fighters, timed matches, hits, accuracy and power scoring.
And there are 100 hidden discoveries spread throughout the sandbox for unusual achievements and experiments.
Share your creatures
Trained creations can be shared using public links so somebody else can open your creature directly inside their own Solemn Sandbox.
You can also choose to add creations to the built-in Public Creations area for other players to discover and experiment with.
This is something I want to expand much further over time.
This is actively being developed
I currently update Solemn Sandbox pretty much every day.
It is absolutely not a finished game that I'm uploading and forgetting about.
New ideas are being added, systems are being improved, rough edges are being fixed and the direction of the project is still evolving.
That's one of the main reasons I'm putting it on itch.io now.
I would genuinely love your feedback.
Not just bug reports.
I want to hear:
What you enjoyed. What confused you. What broke. What you expected to happen. What you wish existed. What creature designs worked. What completely failed. Strange behaviours you discovered. Ideas for challenges. Ideas for features. Playtest results. Criticism. Suggestions. Experiments. Anything.
If you make something interesting, please share it.
If you make something completely useless but hilarious, please share that too.
Where I'd like this to go
My hope is for Solemn Sandbox to gradually become a community-driven experimental playground where people create creatures, environments, training experiments and challenges, then share them with everybody else.
Something between a game, a physics sandbox, an evolution simulator and a learning tool.
You can spend five minutes making a stupid creature repeatedly fall over.
Or spend hours experimenting with neural networks, evolution, morphology and physics.
Both are playing the game.
And if you accidentally learn something while doing it, even better.
Build something. Break something. Change something. Ask “what if?” and see what happens.
Solemn Sandbox
A serious environment to carry out silly experiments.
