Thanks for the encouragement everyone! Deadlines are really great to have, but I really wanted to have the game out this year. Alex tried to convince me that we could do it, but I'm not convinced.
To add some something positive to this -- I'm actually really happy with how the game is coming together. There's still that 'heart' that I mentioned above, but generally everything works well and is starting to look really good. Occasionally there'll be some horrible bug that I find that's been in there for years, but day-to-day it's pretty stable and fun.