Sad that you didn't get the time to finish the core gameplay, but still congrats on working on something for 48 hours and submitting something! It start with that and you'll see how each time you get better and better :) My first GMTK game was suuuuper bad and now after the third one I finally made something I'm proud of.
So don't give up and I hope I see you in next years GMTK :)