There's a few indie titles that are developed by one person and maybe a handful of part timers or freelance people. Turbo Overkill and HROT(Single dev working is Pascal). Most of the time, the retro art style works to the design of the game. Ion Fury uses a opensource fork of the Build Engine(Duke Nuken 3d) and leans heavily into the 90's idea of Cyberpunk and 90's pop culture in general. Dusk is a Quake-like, but I had more immersion in the smooth gameplay then I would in a HD game where the hardware can't keep up with the optimized graphics engine.