Gunmetal is a free-to-play multiplayer FPS that I have been working on for a few years off and on.  It is aimed at recreating the high intensity and fun environment of tournament/skirmish type shooters.  A base kit was used to create the core of the game with simple networking, then high quality graphics were added as well as weapon effects and models.  Detailed environments were created for separate levels using Quixel Megascans and assets from Sketchfab or the Unity asset store.