OK, a quick progress update. I've decided on a theme for the next few levels - which will take the final total up to 60...!! I'll post some screen shots and maybe a video in a few days, once I'm happy with the 'art'.
The Steam Green Light process wasn't too hard to set up and I'm not getting flamed (too much!) by the voters. Time will tell...
I expect to have this released on itch.io and, if they will ever approve my developer account, Indie Game Stand as well. I'm also going to look into a demo and a pay version for Kongregate - it's been a while since I've been over there so I'm going to have to do some reading...
Anyway, enough procrastination, back to drawing rockets...