Gratuitous Space Battles was first released back in 2009, but has received constant care and attention (not to mention several expansions), and something of a cult following since. The premise is simple: you design space ships and then pit them against an enemy fleet. The "game" here is in the design of the ships though, rather than the battle. Designing a ship comprises of selecting a hull and then installing ordnance, defences and support modules in pre-allocated slots. Building a fleet comprises of arranging ships based upon those designs (limited by a budget for each scenario), giving them orders (such as engagement ranges, target preferences and behaviours such as escorting another ship or retreating when under fire).