Hi! I've only submitted to one game jam so far.
It was fun, but also had a bit of deadline-anxiety.
Aim to upload it early to avoid missing the deadline
(Lucky for me they were nice to let me submit it late).
Also, I kinda felt bad when my game wasn't ranked that high, but it's expected for a first try.
So, it's okay if you get a low score and feel sad. I've been there too.
It's good for learning how to make a game, and experiencing a game jam.
It also sometimes gives me ideas when otherwise I wouldn't have any.
(But it usually takes effort to brainstorm an idea).
This is my third attempt at a game jam. Maybe I'll successfully submit my second game.