Oh I learned a bunch. One thing I'm glad I avoided was procrastinating completing features. For example, if you're working on your player's death, complete the whole system before moving on the something else. If you're working on a specific enemy's AI behavior, try to complete the WHOLE enemy before moving on the something else. When you're working on a game with no deadline, it's somewhat fine to bounce around, but when you only have a week, doing so will only start to pile more and more incomplete functions into your game. It's also more speedy in my opinion to do so, which is how I managed to implement a bunch of different stuff in my game. Theres a bunch of other stuff I learned too I think. Jams are surprisingly informative lol