I played a few levels. If you're into the fanwank of Mega Man and Street Fighter together, it's great. The music is fine... SF remixes in 8bit MM style, of course. However, if you're looking for Mega Man difficulty and gameplay, the levels I played are quite short and easy. I'm awful at classic MM, and I had relatively little problem getting through to the end here. Controls are adequate. Only a 40 MB download.
To be honest my computer is kind of crap. 512 MB of RAM, onboard graphics. Garbage. And the damn thing requires 1 GB of RAM, so the music kept cutting out. 1 GB for a Mega Man game! That's kind of ridiculous, although others with modern machines obviously won't have a problem with that.