Hey there, that sounds awesome! I'd say the most important thing is to make something small - you will want to submit something that works than a non-functional bigger idea. Best of luck with it all, and remember to take care of yourself across the week! :D

Try to complete certain functions at once, don't skip around.  For example, if you're working on your character's walking system, finish the whole system as much as you can before moving onto something else.  Otherwise, you'll have a bunch of half-complete systems in your game, and no one wants that!  This is just something that's worked really well for me in my past 2 game jams.

Best of luck!