I really liked working every day, but my personal favorite days were day 3 for Pizza-ed https://thomas-bringer.itch.io/pizza-ed and day 5 for BEAThoven https://thomas-bringer.itch.io/beathoven. The reason is, I completly changed the game's idea in both cases, which was just a ton of fun. For Pizza-ed I completely introduced the pizzeria theming in a generic top-down shooter template. For BEAThoven, I turned a slow, strategic, cute game into an intense rhythm-based game, while throwing away part of the original idea!