Global Game Jam 2018 was my first game jam. I showed up not knowing anyone and only having minimal development skills in the Unity game engine. Nevertheless, I partnered up with a group of three other people, and we managed to make a pretty cool game.
GGJ is the largest game jam in the world. It takes place in late January every year, and anyone in the world can participate. GGJ isn't a competition, but there is a theme you are encouraged to follow in your project each year. The theme in 2018 was "Transmission". Our team came up with the idea of transmitting telekinetic waves. We thought of placing players in the shoes of a mental patient in a straight jacket who can only hobble around, but who's limited movement is compensated for by telekinetic powers. You can use your powers (along with an assortment of blunt objects found lying around the hospital) to escape captivity.
You can download and play the game from the Global Game Jam website. It will only run on Windows (sorry, guys, back then I didn't know much about cross-platform development).