To address your concerns about credits to the OCRemixers, yes, we give credit to all remixers whose music we use in the game. Most of it is in the documentation in the game itself. Also, the mp3 files themselves retain the ID3 tags.
This has evolved far beyond just a Mario game with enemies from other games. It's now its own style. Many of the non-Mario levels will have their own look (i.e. no standard ? blocks or bricks or coins, but they will be reskinned to fit their environment better).
It will also have a deep plot that will explain why Mario and company are traveling around in Dr. Wily's castle, in Hell, and in the Halo world. The plot is one of the most closely guarded aspects of the project. That is why to many outsiders, it looks weird seeing Mario and Samus and Sonic together in one game.
Finally, in the video, here's the full music listing in chronological order:
1. Mega Man 3 "Needles" OCRemix (Dale North, Mustin, Nate Cloud, NyKad)
2. Needleman Remix by Gerald Kaye, used with permission
3. Woodman remix (Screw Attack)
4. Skullman remix (PHOENIX Project)
5. Gutsman Stage MelodiusHardRock (PHOENIX PROJECT)
6. Mega Man 2 BubbleManWantsToGetFunkedUp OCRemix (Disco Dan)
7. Ozmone Plain (Final Fantasy XII)
8. Tetris Type A (Super Smash Bros. Brawl)
9. SMB1 Castle - SSBM Version - MIDI File sequenced by Zagro
10. Crimson Gaze (Raiden Fighters 2)
I also put this listing in the YouTube video description. I apologize for any inconvenience because the annotations did not show up outside of YouTube.