Tonight's update: added the palette changing effect, as well as animations for different enemies. In the finished game, the color change will also affect the music, as well as player and monsters behavior. Colors are not final, of course. I'll get those figured out before release.

Update: it's working in-engine. Not my best work, but it's what I could come up with under the time constraints. I'll try to get it looking a little better if I have the time.