Hastily pieced together for release months after the supposed end of the series, the game is balls-to-the-wall hard because its level design is all over the place and the nightmare system which adds further hinderances only worsens the experience. The disc I have is so scratched up that for years, the nightmare effects would permanently layer on top of one another and I thought it was normal because that's just how sloppily the game is designed. Some of Zero's weapons can actually get him killed if activated in the wrong place and while the Reploid rescue system from 'X5' is built upon, some of them are left so out of the way or directly next to danger, almost guaranteeing their loss. The music is really good though and brings the game up half a star but yea, you could've let this cook for another couple of months and it only would've come out burnt; there's no fixing a lot of these issues without completely rebuilding its foundation.