Damn, that is quite a feat! I barely even know where to start.
Well, first off, a general overview of the song: you were able to make an 8 minute piece not very repetitive amazingly well. There were some parts that I personally felt went on a little long, but honestly I've heard 3 minute pieces with more repetition— including my own— and I would probably chalk that up to my own personal pace for rapidly shifting music anyway. It did remind me of EnV, as you said, but only stylistically. The melody seemed original, unless I'm not thinking of the song. And I like EnV, so... good job...
For the record, I loved the retro part— I felt it was just what the song needed to keep me interested, because I had (after all) already sat through 3 and a half minutes of the same melody. All the synths and other sounds were great... not much I can say about that, as you know.
I'm gonna put in some suggestions here, but I'm not taking off stars for them because their just to try to elevate your music to a new level of awesomeness: first of all, I'm impressed that you used that same melody and chord progression for 7 minutes and 56 seconds, but I don't think it would've hurt to have a key change, or even a new theme somewhere, just to mix things up and give it a certain flavor that I think it could use. (I know I'm one of the few people who cares about that sort of thing judging from other Newgrounds reviews, but whatever.) Another thing you could try is harmonizing with the melody (having the melody overlaid above the original at intervals), which might or might not mean anything to you, but if you're curious on how I'd be happy to explain.
Wow, this ended up being a really long review. My point was, you've come a long way from Kraken, that's for sure. I'll be outraged if you don't get as famous as EnV someday, at this rate. Keep it up.
Cheers c: