Numchuck and the Conquest of Color is a platformer with a dynamic color palette. You play a magical, colorful forest creature, Numchuck, who awakens one day to find his entire world has been drained of color by the cold-hearted creatures of the north. Numchuck is tasked with color-changing his enemies by painting them with one swipe of his magical paintbrush tail, and eventually restoring color to his land. With each enemy you paint, and each fruit you collect, color is gradually restored do the monochrome world.

Further release notes from Eric:

Ok, so I’ve been sitting on a one-level game demo I developed (with the help of a very talented programmer, Tim Sorrels) in 2005, and I figured since the DSi was about to delete which did away with the GBA slot, I better go ahead and release it to the homebrew public while the format is still fairly relevant. 😉 Admittedly there are a few bugs and the difficulty is substantial for this level and the gameplay could use some work, so forgive me- this was my first attempt at game development! But hey, I’m proud of the end result 😉

http://forum.gbadev.org/viewtopic.php?t=16572