The development time was/is roughly about 1 year, and still going. It took this long because it's only a part time project and a very small team (2 people) and a shoestring budget.
As for submitting it for GDWC - I'm not sure because the game isn't complete, but thanks for considering it to be good enough so far :D
Wow that's amazing! I bet there's a lot to do with two people, I made a game in April during a course in school with two other people and I never would've guessed how much work it is so I salute you :D
The competition is an annual thing so if you don't feel like you want to submit your game this year there's always the next :)