I have participated in Slavic Game Jam 2017. I would like to share few thoughts that came to my mind during the event and especially during presentations.
Participation in a game jam is like any gamedev project, just on a small scale. All the rules of a successful gamedev project apply. All the rules of doing a software project apply. You need a good idea for a game, so any method of coming up with ideas (like brainstorming) may help. You need the code, so good programming practices apply as well, so you can implement features fast and not drown in spaghetti code or hard to fix bugs in the middle of the project. Experience in game design and level design is useful. Skill in making good game graphics and sound is essential as well. Some project management is needed too. Even the wisdom about work-life balance apply, because having too little sleep makes you less productive the other day (coffee or energy drinks can help a little bit though :)
There are many books about these topics. What I would like to focus on here is something different - some basic organizational things that can have decisive influence on your performance during the jam. Even if you are a great game developer, you won't deliver a good game (or win, if there is a competition) if you fail on some of these basic topics. They are related to both development process, as well as presentation on a big screen.
1. Come prepared. I don't mean making a game in advance and only adjusting it to the theme during the jam. I mean setting up some basic software environment. If you already have your team, or at least some friends who you plan to team up with, meet together before the jam, decide what technologies and tools you are going to use and set them up. This will save you a lot of time during the event.
2. Take as much hardware and cables with you as you can. You never know what you or other team members may need.
3. Finish early. It doesn't mean you need to stop polishing your game long before the deadline. It means you should strive to have a playable game many hours before the deadline, test it as early and as often as possible, and make first build that you could potentially submit at least one hour before the time is up. Maybe you will crunch and apply critical fixes and improvements to your game in the last moment, but your shouldn't count on that. Maybe the organizers will extend deadline by additional hour, but you shouldn't rely on that either. Even something as silly as compressing your game build to a ZIP file on an old laptop can take unexpectedly long time and make you miss the deadline. If you need to upload the game somewhere on the Internet, keep in mind that everyone is going to do this at the same time, so the transfer may be very slow.
4. Focus on making your game looking good during the few-minutes presentation of you playing it. That's how the game will be seen and judged. Making it fun to play for others or fun to play for many hours is a secondary goal. Of course I don't mean cheating like preparing a prerecorded video. I just mean that you don't need to have 20 levels. It's OK to have enough gameplay for just few minutes, like only a single level. It's even better when the game is fast paced and can be finished during the presentation. You may also cheat just a little, like make a keyboard shortcut for invincibility, advancing to next level or showing final credits screen.
5. Make your game easy to remember and recognize. Sophisticated or generic name and content will make people forget about it. Even if there is a list and an order of presenting games, there is often some chaos happening during presentations. Some games have technical difficulties, some teams just give up, and so viewers may be confused about which game is which. If you design your whole game around a single, simple theme (like "a butterfly") and include it everywhere: in game title, logo/menu screen, and in the graphics visible during gameplay, then everyone will be able to easily identify it and so to vote for it. You want them to later say "I liked that game about the butterfly."
6. Give your game build folder/archive some meaningful name. It should contain the title of your game, possibly the name of your team and preferably some ordinal version number. I've seen game builds called "Build.zip". That's a very bad idea. I know that for you this is a build of THE game, but for others it's just one of the games and so they need to be able to easily identify which one is it. (BTW Same rule applies to the file with your resume that you send to potential employers - don't call it "CV.pdf" :) On the other hand, version number is for you. Believe me, there will be more than one version. Calling any of these "final" is not a good idea, because you will end up with "final final", "really final" etc. :) So it's better to call your game build something like "TeamName - GameTitle v01.zip".
7. Prepare your game for difficult technical conditions during presentation. I've written separate blog post about shapes and colors that you should use: 3 Rules to Make You Image Looking Good on a Projector. Here I would like to add that you should test your game on various resolutions. Projectors tend to have small resolutions. You can also meet problems with sound (too quiet or not working at all), so make sure your game is attractive even without it.
8. Use some margin when displaying things on the screen. It is also known as "safe area". In other words, don't put critical information (like GUI elements) near the edges of the screen. It may happen that the projector is not setup correctly and your image will be cropped, making these things invisible. Same applies to time domain as well as to spatial domain: Don't show important content during first three seconds of your game. Leave some "time margin". Projector may need some time to switch to new source and resolution, so viewers may not be able to see the beginning of your game.
9. Control sound volume of your game. If you learned a little bit about giving speeches, you probably know already that you should speak loudly, slowly and clearly. When you present a game, there is another level of difficulty, because the music and sound effects from your game are played at the same time as you speak. Be aware of how loud they are so that viewers can hear them, but also can hear you speaking.
10. Remove all the distractions that your operating system may experience during the presentation. Receiving notification about incoming Skype call in the middle of your presentation would look funny, but it definitely won't increase your chances to win. Same applies to Windows deciding to install new updates in the worst possible moment on antivirus slowing down your system because it just started to scan your entire hard drive. So for the presentation:
11. Finally, prepare for your talk. Decide who is going to talk and who is going to play the game. Consider how long the presentation should be. Determine what do you want to show, what to tell and in what order. Don't do it spontaneuisly, but rather think about the presentation in advance and discuss it with your team.