As the final twelve hours tick down you might be able to see that at the rate you're going, there is simply no possible way you can finish. This is the perfect time to change direction. For example, throw out half your game design. Make a joke game that is impossible to win.
Ways to finish when all seems lost
Buggy? Find something fun about it and call it a feature!
Only one level? Call it a "battle arena!"
Broken weapons? Make the game an "avoider" with no guns!
Sound broken? Your main character is deaf—or in space!
Not fun yet? Make it a "joke game" meant to annoy players!
Ugly art? Call it retro, hipster, or ironic!
Poor framerate? Make it a turn-based strategy!
No story or characters? This is an arcade ...