If you love 2D gaming, sci-fi anything, Minecraft, Terraria, or just you know, having a good time, then I implore you to pick you Starbound on Steam. It’s currently in beta, so there are character wipes and balancing issues, but it’s one of the most interesting games I’ve played in a while. Basically, you start out stranded on a 2D world with nothing but your Matter Manipulator (all-purpose tool) and you have to survive the elements and gather fuel to make it off the planet. Once you do that, you can fight bosses, adventure with friends, build a fortress, discover dungeons, whatever you want.
You can even find instruments, and do this: