Tips for a successful Game Jam: 

1: Start with a small scope. It’s totally fine if you wanna try to make an hour long epic filled to the brim with monsters… but take into consideration that you will need to map, write story and dialogue, event stuff, AND balancing!!! (Also bug testing but in my experience balancing is the most time consuming part.) 

My honest advice is if you are thinking of making an RPG, start with a smaller type story and objective and build off of that. That way you have more time to balance things and expand on story. 

2: Don’t overwork yourself. Drink water and be sure to take breaks. Game design works best when you are well rested and your mind is in good shape.

3: Remember that finishing a game in a month is a hard task! And finishing a game that is even remotely playable is something to be proud of.

4: If anyone has any other pieces of advice or input, feel free to say so.

5: Just thought of this. Figure out what you will prioritize when making your game! You might not have time to perfect everything. Figure out what makes your idea great and what’s best to polish first. 

Everyone has a different approach to game dev but I personally think prioritizing mechanics over storyline is the way to go. After all, it’s a game not a storybook. Unless it’s a Visual Novel in which case yeah prioritize story.

So I think I gave some suggestions for the last IGMC (the less official one), but I'll repeat a few here:

• Uploads: Make plenty of backups, upload early, use butler if you can (so that you only have to upload updated files), and have multiple uploads: Contest Entry, Beta Entry, Dev Entry, First Entry.
  • Your Contest Entry is what you are submitting. This is fully tested, has no major bugs, and you know the player can get to the end.
  • Beta Entry is basically your 'testing' version. People can play it, but it might not be fully tested yet. Once it is fully tested, you can replace the Contest Entry with this. (Note: You might make a new upload for each Contest Entry so that you have a "last working version"). (Note: If you are approaching the deadline, you should usually make a new upload (you can preload as needed) of your previous Contest Entry upload because if you overwrite, you could potentially end up with a situation where the contest ends and you end up with a broken project that you now can't fix).
  • Dev Entry is basically your 'nightly build' version. This is basically just for yourself, but people can play it. It might be extremely buggy, you might be testing all your new mechanics, additions, etc.
  • First Entry is your first contest entry. Don't touch this once it is made. This is your last resort. If your beta entry was pushed to your contest entry and you discover some major bugs, this is your emergency "At least I have something I can submit".
  • If you are using butler, pre-upload your game. All your assets can go up first as it is easier to remove unneeded assets than to add them. This way, when you are hitting that time crunch, you are only uploading say 5mb instead of 500mb.
• Time: Plan out your time. This has to do with Time/Project Management.  Prioritize KEY elements of your game and then add additional elements as time allows (but make sure you plan things out so that you can expand easily). I'd check out the Eisenhower Matrix if you aren't used to time management.
  • Make your project complete at about the halfway mark of the contest (compared to your start time). This gives you time to test your project, upload a working version, and thus at least have a finished entry. You can expand if you have extra time. 
  • Use any time you can. Even a few minutes here and there can make a difference. Keep a notepad on your to jot down any ideas that pop up, do some pseudocode, etc. I often hear people saying that they didn't have enough time, but often people don't use all the time they have. You'd be surprised what even a few seconds can add up to. When you shower, when you are taking care of your needs, such as eating, when you are walking to a location (if safe), etc. are all examples of times where you might be able to think and plan things out. (Unless you have some issue that actually stops you from thinking during these times, consider using such downtimes).
  • Project Management can help a lot, but if you don't know how to do it already, don't try to learn the more complicated methods now. There are some simpler methods though, such as tracking. For those that don't know project management, here are some questions to ask: "Who will do what tasks of the project?" "When will each person be doing each task?" "How does the time look? Are multiple people doing nothing for a certain amount of time? Is one person doing 10 tasks at once?" "Which tasks depend on another task to be finished and are there any workarounds to work on these tasks early?" "Where are our potential bottlenecks?"
  • Remember to overestimate the time needed instead of underestimating the time needed. If you plan to use 3 weeks to do a task and end up only needing 2, great!  If you plan to use 3 weeks and end up using 4, you might not complete the project on time.
• Find a source of motivation that will keep you going when you start to lose steam. If you don't lose steam, great, but if you start losing steam, have that source of motivation to help push through. It can be multiple sources. This can also be a source of positivity for if you start feeling depressed or burnt out.
• Pace yourself. This has a bit to do with time and planning, but pace yourself at a manageable rate. This can be different for everyone, but you don't want to burn out if you can avoid it.
• Breaks: Every hour or two, take a 15 minute break from the computer. Every 3 hours, let your mind just wander and relax. The exact time might differ from person to person, but let your body (eyes, wrists, etc.) rest and let your mind rest. In fact, you should let your eyes rest whenever you don't need to be looking at your screen(s).
• Warm ups. Do some dynamic stretches/warm ups before you start working on your computer if you can. This can help with wrist fatigue.
• Save often, backup often. If you have a cloud service (such as itch.io, google drive, etc.), use it at least once a week to backup your game. Every day, try to make a backup onto your computer, an external, or a flash drive. Every 30-60 minutes, save. Every time you finish something important, complex, tedious, or w/e, save! This way, you minimize work/progress loss if something goes wrong.  If you can, save multiple iterations of your game so that you can go back to a previous iteration as needed.
• Don't upload every version of your game. I've seen this. Someone exports their game to their development folder (don't do this, export to a separate folder, not inside the project's folder/subfolders). Then the next time they export, it exports their game, with that previous version, into their development folder. Suddenly, you have a 50 GB upload that is actually only 400mb of content because there are like 60+ iterations of the game in the upload. And then they wonder why their project is taking hours to upload... (dev: "itch servers are really bad today, it is taking me 23 hours to upload my game!" /me looks at upload the next day me: "I wonder why...")
  • Note: I say subfolders because exporting your project to your faces folder does not help with filesize.
  • Note: If you upload every version of your game in your project, expect the judges to grab a random version of the game. They have no reason not to and believe me, if they should decide to do so, they will probably somehow manage to pick the worst version.
• Test your game after it is uploaded. That means download the game and test to make sure the downloaded version works.
• I recommend writing out a project proposal/game design document. Like pseudocode for programmers, this can help with organizing your thoughts. This doesn't necessarily have to be physical, but physical can make it easier to work on than a mental document.
• Keep a healthy schedule. Don't start sleep depriving yourself, malnourishing yourself, etc. for this project. You want to remain healthy as a healthy body and mind will be more efficient in the long run. 
• If you need to crunch at the end, it usually means you didn't plan well enough or your project was larger than you could handle. For this reason, I heavily stress planning. Aim big where you can, but also know what you can handle. It is okay to aim a bit larger than you feel you can manage, but also know what you can cut out if time becomes an issue. For this reason, I suggest what I mentioned before: Plan for a finished project at the halfway mark, THEN upgrade your project from there. This way, you already have a foundation to work from and you can aim for the stars with the time you have left.
• Test your game. If you can, have friends play and give you their thoughts. You know your game very well, so your experience with your game can differ greatly from someone else. What might seem obvious to you might seem completely obscure to someone else. Unless you have multiple selves, you generally won't do well testing your own game. Even if you do have multiple selves, it is still worth having an outside perspective since testing takes time. Time that you can be using to fine tune things.
• Take my advice with a grain of salt. I have never won an IGMC. In seriousness, note that every person/project/team is different and while these general advice may be a good starting point, your specific needs may mean that these advice won't apply to you or may not apply as is.