We are hobbyists working on hobby projects. Don't expect to get paid for your work, usually we also don't sell our outcomes but give it away for free. In case the project creates some value (competition prizes, sales, ...) this is split equally among all members unless the team decides otherwise or some team members donate their part to other team members or the overall team.
We will select a project manager that helps coordinate project activities, but this position is rather understood as a service position than as a "boss". Please keep this in mind. Unless one person is doing 80% or more of the work, the project should be advertised as a team project, not as a project of "XXX and his team"
Others in the team might be quite busy with their other duties, and naturally, the time people in a team can spend on the project can vary. If you are able to spend more time on the project, it is appreciated, but you have to understand that others might not be able to do so as well. We are hobbyists - accept this.
Usually, we coordinate by assigning persons to dedicated areas (e.g., level graphics, title graphics, music, coding, story). Please ask others for feedback on your part and accept the feedback. Please give feedback to others in a respectful way. Don't change things in other areas without asking. Don't ask for being credited for another area, this is upon the discretion of the person responsible for this area or the overall project consortium.
Especially in online communication, even a message that is meant to sound neutral could upset other people. Everybody can have a bad day. It is really important to keep communication positive and encouraging, even under stress. Please be especially nice to younger team members; they are probably less experienced with the project work and would need encouragement.
If something bothers you, discuss it with the team or the project manager. If you don't discuss an issue and just stay silent the thing that bothers you might happen again. Also being silent on the project might create further irritations. Please also try to be available on the team chat if your schedule allows it.
More eyes see more, and you are not alone in the project. You might be very convinced about the work on your part, but others might have a different impression. Please take your time to listen and discuss changes.
However, if you take responsibility for a part, please try to keep your promised deadlines. If you feel unable to do so, please inform the others and also accept help. If you get significant help in your area, offer the helping person to be credited as well for their task.
Copying code, using copyrighted music or images can generate serious problems for the project, even if it is just a hobby project. Some gamejams, for example, require publishing the game content as open source, which does not work with copyrighted content. If you are unsure with a certain part, please discuss with the team before integrating it. Apart from legal issues, note that a copying an existing game concept or story is much less innovative than coming up with our own creative ideas!
Imagine working on a big project, and suddenly one of the colleagues wants to leave and take all their contributions with them. That might kill the whole project. To avoid such a situation, the content you submit to the project is a gift, giving the other the certainty that the project's current state won't collapse.