Game Jams are where you have to make a short game, or usually just a demo, within a small amount of time. This time may range from mere hours to a week. These games are usually more basic and set around a theme provided at the start to the jam.
All of these games could be put under "Game Jams", but Night Walk is the only one that technically isn't a jam game. While the demo was made in under 48 hours, I spent a few months on and off to polish it and add more levels and music. It also didn't come from a Jam, just from playing around with ProBuilder!