The Vivitar Ultra Wide and Slim is a recent favorite of mine. It’s made of plastic and has a fixed shutter speed and aperture, just like dozens of other plastic cameras. What makes the Ultra Wide and Slim special is a wide 22mm lens and LOMO-like vignetting.

35mm ultra-wide angle 22mm pan-focus lens using plastic film 1.2m ~ ∞
Aperture f/11
Shutter speed 1 / 125
Size: W100 — H58 — D26 mm
All plastic lightweight 75g

See for yourself!