I'm not sure about the longer term.
Maybe it might be better to have small and clear goals like:
- world/map generator
- cellular automata/Game of life
- Arkanoid game
.. (can be poll)
Which do not take much time, let's say max. 2-3 months.
With a clear announcement of the competition, end and vote on winners.
Benefits:
- simple/strict rules works
- cca 4-5 competitions per year - "Wow, it lives here"
- if you are busy right now, no problem, you have opportunity join next time
- we can compare code because all participants have same task