It's really polished game, but didn't find the theme part there. Instead of GB use of km or miles may make sense, but if GB stands for anything special, you have to share it in the gameplay. The graphics was nice, simple and clean.
I suppose I should've made what you're doing more obvious. GB stands for gigabytes, because you're gathering data about the planet below. The game's page somewhat clarifies that. Thanks for the review!