Hi! Yes, all 50 games and the launcher itself are all made in GameMaker. Originally some of them were made in GameMaker 6, 7 and 8 but they were all updated in GameMaker: Studio before the pack was put together.
Cool. I'm just starting out making games in GMS2. It's cool to see a fairly large variety of projects. I like to try and figure out how the games are coded as a mental exercise.
