Unfortunately, the theme for the Global Game Jam actually suggests play mechanics, and that's a pretty fundamental aspect of the game. For this game jam, the theme was "What Do We Do Now?" which you can't just shoehorn into an arbitrary game. I tried cramming the theme into a pinball-style game, but it wasn't really fitting. It might be possible to superficially include the theme in certain types of games, but doing the theme justice really requires hours of quiet contemplation. What makes things harder is that you're also trying to assemble a team at the same time, and it's hard to know what sort of skills you need. And you can't charm people into joining a team if you don't have a good game idea, but there's no time to come up with ideas because the teams are forming fast and you'll end up being left alone if you don't move fast. I was thinking of joining some other team, but almost every team was working with Unity, and I don't know that system. It was quite surprising actually. Everyone was using it, even for 2d games. I tried to get into Unity in the past and failed. And watching videos of the 2d stuff, I thought it was a little fiddly since the UI was mostly designed for 3d. As a casual game player and designer, I shy away from Unity because it comes out of hardcore gamer traditions and it doesn't work well in the web browser, a must for casual games. But everyone was using it for everything. I might have to start learning it after all.
In the end, I decided to focus on the "we." What do WE do now? People with different interests who must come to a collective decision on something. As a casual gamer, I focus entirely on solo games because casual gamers are just looking for a short diversion. Also, I'm forever alone. Where would I find other people to test my game with? Multiplayer games tend to do well at game jams though, and there were other people there I could maybe coral into trying it out, so I decided to try making one.
I tried to come up with different scenarios that would fit this party game style of multiple people needing to make a collective decision. Nations deciding on something? A boat or flotilla moving in different directions? Also, how would the decision be made? What would the differing incentives be? Would there be bartering? Could you change the rewards of different decisions? Would there be different strategies to winning? In the end, I couldn't think of anything good, so I went with a spaceship that different people want to steer in different directions. I dreamt up an image in my head of a dysfunctional space bureaucracy, with an elaborate power sharing agreement among equal nations who constantly bicker about what to do and who sabotage each other constantly. It's like the EU or the UN in a space ship. That sealed the deal.
I had the thrusters working by about the 24 hour mark, so I had someone playtest it. I initially used tank controls for the people, and that was too messy. The thruster mechanic was also way too complicated for people to understand. And since each of the four players were so far from each other, and anyone could spoil things by manipulating the thrusters, there wasn't much interaction between the people. I was thinking of adding some sort of cooperative elements where there might be events where everyone would have to cooperate to man some larger system as in Space Cadets or Space Alert. Events seemed like a lot of work though. Instead, I added a coin feature to let people make deals where you could exchange coins with people in an attempt to cut deals. I then found I had enough time for confrontational-like elements like pushing and shooting.
Then, time ran out. The fundamental navigation at the heart of the game ended up being too complicated. The physics of turning the ship with counteracting thrusters is too messy. With the thrusters so far away from each other and anyone being able to spoil things by turning the ship, there also isn't enough interaction between people. In hindsight, I should have started all the players in the center of the ship, which would have allowed for a non-circular, non-symmetric ship but still be fair for all the players. I should also have had more limited thrusters (maybe only two, possibly with some mild turning thrusters too) so that it's not so complicated to figure out how to control the ship.