Play Rockman (Japan) [Hack by Tokkan Kouzi Kanrinin v1.0] (~Rockman Neo) Online

Game Overview

This is a wild hack of the original Rockman (Mega Man) for NES—someone went and tweaked everything from the robot masters to the stage layouts. At first glance it looks familiar, but then you notice the weapons behave differently and some enemies show up where they absolutely shouldn't. The difficulty's all over the place, with some stages feeling easier than the original while others will make you question your life choices.

I got wrecked by the first boss three times before realizing his pattern was completely changed. The music's still that classic chiptune goodness, though some tracks have subtle remixes. If you've played the original to death and want something that keeps you on your toes, this weird little mod might just do the trick.