For me I started out with some ideas for social infection games, and was messing around with core to try and get mechanics working in a simple state. After over a day of working, I figured out I wasn't familiar enough with Core, Lua, or 3d games in general to be able to get something into a workable state in time. Anxiety started to hit and overwhelm me, but I managed to push through and refocus myself. My goal was to complete something and it was still very achievable. I fell back to what I knew the most about, rpg maker, and part of what was nice about falling back to something more familiar was trying new things with it. Captive is the game I managed to complete:
https://itch.io/jam/extra-credits-game-jam-6/rate/739230
THEME: For the theme I went with a use what you know approach. I have BAD anxiety that completely cripples me some days, and I've had to learn many tricks to get myself functional when it comes up. I've wanted to make something around it to share my experiences with people for awhile, but there is always a difficulty in explaining abstract things to people. So take care of your anxieties was the theme, and I used a prisoner analogy to try and make it relatable.
Extra History: I threw in an easter egg from one of my favorite quotes from the web series in a slightly off path place.
Extra Retro: The extra retro challenge felt more of a stylized art challenge. I've played enough retro games with those pallets, if you don't have a strong vision when using them they become vomit inducing. I wasn't going to be able to go that way.
Extra Distance: It's kinda there, kinda not. The goal is too escape and put as much distance between you and your prison as possible, but I do offer an option to confront your warden.
Extra Translation: There are tiles with a magic language on them used for one of the spells. An NPC that can't use magic will reference them as gibberish at one point.
My own extra challenge, no music: This was partially brought on by time constraints and partially because I had never tried it and it sounded interesting to do. I added in ambient sounds and tweaked them for each scene. I wanted to do a little more with them, but exhaustion hit me too hard by the end and I just had to accept what I had.