If crowdfunding was a thing in the '80s, maybe this is what Star Citizen's umpteen millions in funding would have eventually produced. As it is, it's a free webgame to play while you wait for the full game's creation. It's called Hyper Vanguard Force IV, and uses pixel recreations of Star Citizen ships and concept art. There's even a plot, detailing why you need to shoot literally all of the spaceships.
Its flight model isn't quite as detailed as what the full game is aiming for. You control the ship by dragging your mouse around, and fire with the left mouse button. It's pretty basic, but also a fun way to waste away a Monday morning.
You can play Hyper Vanguard Force IV here.