https://www.pcgamer.com/mothergunship-demo-teaches-the-finer-points-of-gun-crafting/

The bullet-hell FPS Mothergunship is a game about making guns and firing guns being co-developed by the guy who made Tower of Guns. A taste of how those various gun parts will come together can now be had by way of a "Gun Crafting Range" demo that went live today on Steam. 

The demo begins with a simple bit of gun-upgrading and a quick trip through the FPS gun range, but ramps up in a hurry with more and different attachments, and more and different things to shoot at. Guns become increasingly complex, dangerous, and ammo-hungry, and the need to balance raw firepower with energy conservation very quickly becomes apparent. I whipped this thing up, for instance (it's a terrible mess of a design, but I was in a hurry), and it's good for approximately 2.4 seconds of fire before it's dry.