This game idea is partly (mostly) based on Kinder Surprise toys, which are awesome to the max. Or were. Back when I was a kid. In the late 80s. Which was also, coincidentally, the last era where it was socially acceptable to say "awesome to the max".
Capsule World is similar to a world-based God-Sim such as Civilization or Black & White. You have full control over the development of the little area of the world that your people reside in, and partial control over the rest of the currently barren planetoid. In order to populate your world with a plethora of interesting specimens and artifacts, and also increase the physical, cultural and educational boundaries of your existing followers, you need to resort to the "divine tumbler": Basically one of those giant egg machines you find in arcades and outside convenience stores where you crank the handle and a capsule comes out - only really, really big. The resulting capsule, in the context of the game, can contain almost absolutely anything. However, once hatched, the capsule's contents must be placed somewhere on the Capsule World - at which point it will blend in and become part of it.
These capsule contents can vary in their usefulness. Almost all have an inherent value and will, at the very least, make your world a little bit more interesting to live in. They can range from mundane tools, such as giant deposits of valuable minerals or metals as well as lush forests and seas, to the slightly inconvenient, such as dinosaurs or the undead. Once added to the world they become an indelible and inseparable element of it. Your denizens will react to their new gifts/neighbors as best as they are able, though the net gain might not always be as positive as one might hope.
Your main tasks are to concentrate on the safety and happiness of your people and integrate these new random elements as best you can. The game will pause the action going on planet-side every so often for a compulsory capsule addition, though you are able to add new elements at any time yourself. More capsules means more variation in your world which will ultimately net you a higher score as the world eventually develops into a somewhat strange but beautiful and (importantly) "complete" world. It's recommended you get a new capsule every time you've stabilized the effects of the previous capsule - this way you can maximize the benefits of the additions and their enhancement on the world without losing too much stability among your citizenry (along with not losing the citizenry itself).
While you can control the population as a whole, defining where their research and development should work towards (in proper Civilization fashion) as well as setting up defenses and such, the people tend to think and act for themselves. This includes curiosity, something inherently human and inescapable. Your people will attempt to explore and interact with any capsule additions as they appear as dictated by their natural curiosity. This may lead to many unfortunate incidents as they come to terms to what has just landed on their world and their changed reactions to the world and to you (since, as their god, they blame you for everything). It's up to you to manage those incidents amongst everything else. Your people aren't stupid though, so anything dangerous will be given a wide berth if too many lives are lost and anything beneficial will be mined and exploited as effectively as possible.
The people will also, charmingly, come up with their own ideas about what these new additions are and why they were placed here, based on the kind of history your world has had so far and their relationship to their maker. For instance, if most of the capsules have been bad news until now, your people will be generally pessimistic and may view the advent of a genuinely advantageous capsule as a trap, something new for the tyrant deity to break their wills with. Inversely, if it's been nothing but milk and honey for your people up to this point, something like the coming of gigantic deadly insects will be accepted gingerly by your people as some adorable buzzy friends to play with (until they start eating people, that is). These analyses from your people are generally based on their overall happiness score which will eventually even out to a moderate and informed level as they grow in intelligence and wisdom. A mixture of both good and bad additions is necessary for the people to retain a sense of cautiousness as well as happiness.
Important focuses when developing this game will be to include a highly playable and configurable god sim with a truly diverse cast of additional elements to establish on the world. Ideally, such a set-up will recreate a near endless amount of variations and, therefore, a considerable amount of replayability. A finished world, with all the strange elements integrated effortlessly and overlapping one another, along with an ongoing timeline of what joined the world and when, as well as a diverse population of people thriving due to (or in spite of) the additions should be a thing of wonder for the player to want to look back on, or perhaps share with others.
