Not everyone is proficient is all aspects of game making... But if you don't have a team to complement your skills, jams are a chance to try your hand at something new! Let's just figure out some accessible options.

Being bad at graphics

You don't know how to draw? No problem.

One option is to just deal with it, and make a game that doesn't require pretty art. Games like Thomas Was Alone and 140 were successful commercial games built with basic shapes of various colors. This is what we call developer art, and it's perfectly acceptable! West of Loathing, featuring stickmen is another example. Of course it may not get you 10/10 ratings in Graphics, but simple graphics can still be super fun. Even in 3D.

Another popular option is to go for pixel art. It can be super fast to make, and with some effort it's easy enough to make something presentable. Realm of the Mad God is an example of successful game that has pretty simple (one could even say average) pixel art. Look through a couple tutorials to understand the basics, and don't be afraid to borrow the style or choice of colors from references.

Finally, you can just grab third-party art and submit your entry in the Unranked division.

Check the Resources page for a list of graphics software you can use.

Being bad at sound & music

I have good news: there's several, super easy ways to include sounds effects in your games. Making music is more involved, but still doable!

Regarding sounds, the Resources page has multiple tools for you to try. Your first option is to go down the sound generation route, using the super-easy bfxr software and the likes to produce cool, often-arcadey effects. You could also record sounds yourself with Audacity, assuming you have a decent microphone. Finally, you could just grab existing sounds, which is allowed even in rated competitions, as long as the assets you use have a permissive license.

Now for music, if you don't have any experience but still want to start making music, you can look around the Resources page and give a try to software like Bosca Ceoil. If this is new for you, it will definitely take some time to get comfortable with the tool and not cringe at your music too much, but it's not that hard to get something acceptable for a jam game.

Alternately, you can just grab existing music submit your entry in the Unranked division. Or, you now, not have music, maybe even no sound at all, which is also acceptable.

Being bad at code

Without knowledge of code, there's still plenty of options nowadays for making games! An option is to use genre-specific engines (e.g. for text adventures or RPGs) which are just point-and-click interfaces that let you build your game. More recently, great general purpose engines that still don't require code have started appearing, letting you build any type of (usually 2D) game.

Check the Resources page for a wide range of engines to try, and find the one that suits you best. Discovering an engine during a jam can be frustrating, so it is probably best to at least do some tutorials before the event starts.

"I'm bad, I'm bad, really really bad" *

If you're just new to all aspects of game development, you still have no excuses! Engines like Twine (text adventures) and Scratch (2D) are literally accessible for everyone. You can even enter without making the art or sounds yourself, by choosing the Unranked division.

Depending on what you want to learn, the suggestions above are still valid for advice on each aspect of game making.