You’ve planned your game and kept yourself from growing it to big in the planning stages. Next, you’ve quick prototyped your mechanics to make sure they work.
So what do you do now? Use a systematic approach. Fill out the whole database at once, a tab at a time. Don’t jump back and forth. Doing everything of the same type at the same time will make you faster. When you start and stop on each approach, you are taking a bit of time to get used to doing that process again.
Is this the most FUN way to design a game? Not really. I know that I enjoy just doing what I feel like when I feel like it, but a structured approach allows you to do more faster. Of course, if you feel that the loss of fun is going to push you away from wanting to work on your game, maybe try to break each section down into chunks. Allowing you to move between different tasks, but still spending a bit of time on each one.
Everyone has to find the balance that works for them, between fun and speed, but if you want to finish a game in a short amount of time, you may have to lean more towards speed. Let’s hope that your speed gets that IGMC entry finished, good luck!