You should resque ships trapped in asteroid field. Convoy them to the gates, it's a safe zone. You can convoy more then one ship at once, but remember - the more ships in convoy, the more chances they'll get hit!
I wanted to make a space shooter for ld40. But then I found out that theme is a little bit odd for this and I don't have any time to spare. So it should be a small game. That's when I got it. Snake is a perfect example: the bigger u are, the harder the game is. But I still wanted to make space smth. So I ended up with the idea of space snake aka convoy of ships. Making vanila snake is kinda boring, so I added asteroids. Here we are :)
I had only 4 free hours, but I really wanted to participate in LD40, so there it is! :D