The human immune system is one mad marvel. It monitors our physical well-being through a series of rigid precautionary and at-the-ready defence systems. It's governed by an army of cellular bodies carrying out their respective duties, in order to repel invasion from hostile viral and bacterial agents.
With that in mind it's no stretch to imagine your role in Ballistic SE as that of a renegade code hacker who must break into a totalitarian empire's sophisticated online immune system. You are a single invading aggressor in a wild, Gibson-esque digital grid; a lone orb versus a seemingly never-ending barrage of swarming enemy sentries. You'll want to take down as many as possible - it's just the staying alive part that isn't easy.
Viewing Ballistic as a sort of digital ecosystem under attack (you can still pretend you're Neuromancer's Case or Neo if you feel the need to justify your assault) may seem like an odd comparison, but it makes sense when you see this dual-stick shooter in action. Since each level's set number of enemies can be cleared in a matter of minutes, you'll quickly learn to tell the behavioural characteristics inherent to each of your colour-coded opponents.