Seize the Day was a calendar program made by in 1994 by Buena Vista software. It features graphics that at the time, were revolutionary because of the way they handled color cycling. These images were static bitmaps, but by changing color values, they appear animated. What is also impressive about these images is that they had full day night cycles built in, rendered also through color cycling.
A few years ago, a html5 version was made. A copy was uncovered online and there is a way to use the program through DOSbox. As well, one of the original programmers for the project, Iam Gilman, has thought of the idea of remaking it, open sourced, for modern machines.