Even though I was more looking at the Jam in the beginning, I tried to stick to the compo rules and actually succeeded!

What went right:
-Coding proceeded way faster then expected. I aimed low (threw away the idea of randomly generated universes pretty quickly) and had no unexpected problems. I’m not really good at math, so I expected many problems with orbits and rotations, but everything went smooth.
-Gameplay finished by Saturday night. I got that suggestion from the LD subreddit and tried to crunch in as much as possible on Sat. While some important features (time, wining/losing, score) weren’t finished by then, it left enough room to finish the game up during Sunday.
-Visuals turned out “ok” especially for my non-existing skills as an artist.
-Time was biggest fear in the beginning but even though I was out on Saturday for a couple of hours, I was able to finish Sunday night by midnight CEST (three hours before the compo ends)
What went wrong:
-I started out with a different resolution and halfway through I realized that the screen didn’t stretch properly when I ran the game in fullscreen. I upped the resolution to a higher, more common resolution, but so much was hard-coded that I couldn’t change the planet sizes anymore, which made them very small in the final game.
-Collision was a bit tricky, because I forgot that the rectangle around a sprite doesn’t rotate with it, making the collision between the rocket and a planet really wonky. I ended up adding a small 2×2 px hitbox, which orbits around the rectangle’s origin to (almost) match up with the tip of the rocket. Again, this process went much smoother / faster than expected.
Summary:
I aimed low from the beginning, but considering this is the first Ludum Dare and the second game I ever completed, I am very proud of the result. It was also great hanging out with everybody in the IRC and seeing other games develop and everybody being really passionate. It was a great experience that was totally worth a weekend of hard work and little sleep, keeping me excited all the way through. I am looking forward to December!
I am sorry the game only runs in Windows and has to be installed, but XNA 4.0 is the only framework I am really comfortable with. I will try porting to Linux / Mac with MonoGame in the next couple of days, but I am not sure how that will turn out.
I want to thank the makers of Gimp, Aseprite, sfxr and Microsoft (Visual Studio / XNA) for putting out such great tools FOR FREE that allow guys like me to get creative.
You can find the game here: http://www.ludumdare.com/compo/ludum-dare-24/?action=preview&uid=15165
There is also a short gameplay video on YouTube here: http://www.youtube.com/watch?v=U47zYXkmyyY&feature=plcp