Although I'm over a week into 2020, I'm still trying to decide on the major goals I want to achieve this year.

Current candidates are:

Run a marathon
Running a half marathon was a challenge for me. I'd like to take part in another one for 2020, but I feel like running a full 26.2 miles will be a much greater challenge. This goal also fits in with my "don't make all goals revolve around writing software" rule for 2020.
Release a game
I completely bailed on writing games in 2019. I keep telling myself it's something I enjoy doing - at least I think I enjoy it - but I never seem to make the time to create anything. For 2020 I'd like to release something.
Learn some physical skills

I've done bodyweight exercises on and off for a couple of years, but haven't done enough to really improve in any significant way.

I'd like to actually put some effort in this year and learn a few of the more advanced skills. I don't expect I'll be able to master a handstand, but I'd like to be able to manage a frog stand.

Write more frequently
Every year I say I should write more and I rarely do. Last year was my best year for writing, and I wrote more posts for this site than any other year. Although I already have a "blog more" goal set up on beeminder, I think I'll need to narrow this goal down to achieve it.
Complete a maniac week
I love the idea of a setting aside one week a year to run a maniac week. I've taken part in a couple of game jams and they're always extremely productive. Focusing some of that energy on my goals would be highly beneficial.
Increase my earnings

Last year my freelance earnings were down about 20%. This was partly because work was slower, but more likely because I got lazy towards the end of the year and didn't take on as much as I could. I feel a bit icky about publicly committing to this one. although I'm not really sure why.

I'd also like a portion of my earnings to come from "passive" income sources rather than direct work.

I also have a list of around 40 minor goals for 2020 that I need to figure out. I'm trying not to get too hung up on having things 100% decided by January.