The game sees players put in control of the defense of humanity's last surviving metropolis which is under threat from mysterious alien forces (as well as other miscellaneous bits of space debris).
Armed with a railgun, and a small stockpile of nukes, your job is to protect the city from incoming collisions in order to fight another day, with the option being offered between waves to pick from a series of upgrades to better prepare for the next assault.
Already the game is a ton of fun to play, and according to its developer, there are a lot of incredible features that will be coming to it over the next 6-12 months while it is in Early Access. This includes online/local leaderboards and controller support, as well as more upgrade choices, enemy types, and an expanded soundtrack.
If this sounds like something you'd be into, you can pick it up now from Steam for just £4.49.