Populution256.zip contains the version of Populution that works with 256x256 bitmaps. If your computer is slower, use this version. The example maps are designed to be 256x256, so they play more interestingly with this version.

Populution512.zip uses 512x512 bitmaps, runs slower, but accepts colors as a number between 0-255. If you have a computer made after 2003, probably use this version.