An article on Gamespy discusses the problems inherent in translating classic remakes to modern consoles. "For reasons both technical and probably cultural, most video game companies not giving their reissued classics the polished, flawless presentations that they deserve. For example, take Mega Man 2, from the soon-to-be-released PS2 package Mega Man Anniversary Collection. When you load up this new version of Mega Man 2, you may think that the pixels look chunkier than they used to, that the screen flickers rapidly, and that the graphics are somewhat blurry. That's because all of these things are true. The low-res, 256x224 graphics of the original NES game have been line-doubled for display on the PS2, are run in an interlaced (flickery) screen mode."
Read more at Gamespy.