This question comes up from time to time, with some desire towards coming up with a standard guideline to follow, but I've never been able to pose one that wouldn't restrict our flexibility. By the same token, I don't want to be as flexible as Discogs. My philosophy goes something like this:

1. For solid game/anime composers or arrangers, you can submit "works" albums that are outside our scope if you think they are of interest.
2. To prevent clutter on the artist pages, be mindful of the ratio of in-scope to out-of-scope albums. We don't want someone with 3 VGM credits to have 12 works albums. I don't have an exact number to give for a ratio, but I hope that some common sense is used.
3. The standard is much higher for performers. I don't really want solo albums to be submitted for a vocalist that was on a few animes. (Plus, vocal albums are a lot of work for staff to fix if they aren't done carefully.) You pretty much need to be game-related on the level of I've Sound to merit some works albums.
4. Doujin circles who release albums at Comiket are generally an exception to these guidelines; we are much more lenient there. However, artists who release albums at M3 are not. We cover comiket fairly closely, but we only cover game/anime music at M3.
5. If you submit a works album and do a poor job (incomplete or wrong information), staff is free to reject the album at their discretion. I don't want to waste limited time on something that isn't our focus.
6. Original instrumental music is of higher interest here than pop vocals, so those albums should take higher priority for 'works' submissions than albums full of standard-fare vocals or cover-song arrangements.

Do album that contains one or more anime/game/publication/etc.... track(s) are still OK to submit? Whoever the artist is?

An album just needs one game or anime track to qualify for submission.