There's plenty of algorithms to scale up pixel art (I prefer hqx personally), but are there any notable algorithms to scale it down? In my case, the game is designed to run at 1280x720, but if someone plays at a lower resolution I want it to still look good.

Most Pixel Art discussions center around 320x200 or 640x480 and upscaling for use in console emulators, but I wonder how modern 2D games like the Monkey Island Remake look good on lower resolutions? (Ignoring the options of having multiple versions of assets (essentially, mipmapping))