I think you might not realize the duration of the contest. I made it the DAY that the jam started. 31 days in October and the event ends a little before midnight on the final day, but started midnight on the first day so in total, you have 32 days. (technically 31 days, 23 hours, 58 minutes, and 59 seconds). Aka. I made this in about 8 hours (minus the assets, which were for my 2017 entry post contest version.
(This was sort of a challenge from the 2017 discord channel to try to make a game on the first day of the contest).