Sprites extend by one pixel width vertically

(Up to Tricks and glitches (first generation))

In some versions of Amiga WinUAE, the sprites for worms, projectiles and in-motion gravestones will be rendered twice on top of each other, resulting in an effect that appears to extend the pixel width of the sprite once vertically to the right.

In worms this creates a sort of "fat worm" appearance. With in-motion graves it makes them appear slightly chunkier, although this disappears once the grave has settled and becomes destructible terrain.

Cause

This issue is believed to have been caused by WinUAE's inaccurate subpixel emulation. Later, in WinUAE 2.3.1, this issue was supplanted with an issue where active sprites were rendered one pixel to the right of their actual location". This bug has since been resolved.

A similar issue occurs in FS-UAE, a multiplatform Amiga emulation which is currently believed to have no subpixel emulation.