This is a good game for your first game made, especially in a game jam. If you want to improve on this game, here are some suggestions:
-Make the player move faster.
-Make it so that the player can craft different kinds of items instead of just rubber ducks and robots.
-Increase the timer from days 7 and on. It's impossible to craft all of the items on time unless the player uses an exploit. I found out that the best way to beat the game is to continue moving while Santa's note is on the screen and while the timer disabled. This way, I could craft all of the items on time.
-To remove the exploit I've mentioned above, make it so that the player cannot move until they close Santa's note.