Reviews:
Heated Plasma Gun: I'm sure you're tired of us saying that you need to watch your keys, but it's still true. At this point, I'm mainly just surprised that ZtM and PS haven't helped you out with this. Overall it's really not a bad arrangement, you have good instrumentation and a good soundscape; if only those keys lined up during the vertical arrangement sequences I'd be enjoying this a lot. Although wow, I was expecting a brief Contra cameo, not 1:10 of a 5:23 mix. It goes well (again, ignoring the key mismatch), and I guess if you don't expect to win votes anyway, why not?
Storm the Gates!: This is actually my first time hearing this, as the WIP came in late and I didn't have free time this last weekend. It's not as bad as you'd led me to believe. It has a good, driving, dirty rock sound. It's certainly unpolished, and the ending is pretty bad, but the arrangement and instrumentation are solid. Sorry you got stuck with Duo, though, I can tell you couldn't figure out a great way to make it fit.
Wily Must Die: I don't like criticizing singing voices, because it feels very personal, but in this case I know you can sing better than this. Definitely an off day for your voice here, I can hear you straining in places and there are more than a few flat notes. I also feel that the Wily part gets repetitive, especially since I heard only a few seconds of Quick Man, and Proto Man is in the intro only. Obviously I have no complaints about production.
For Everlasting Peace: Some odd timing issues here, and a few sour notes. I know as well as anyone how hard it is to get orchestral arrangements sounding good, so keep working on that--your soundscape definitely isn't sounding full enough, and the strings in particular sound artificially jerky in places. It's a good arrangement, though, other than the abrupt ending.
Blam: I think it succeeds at what it's trying to do. I hear nothing objectively bad about it. But the sources are still tough. I can tell they're there now that I know what to listen for, but when you change the rhythm of the notes, switch from a major to a minor key, and focus on very small sections of the source, I'm not sure it qualifies as a remix anymore.
Prototype #2: Epic lyrics. Use of Proto Man is pretty light, and in some of the rap sections it was hard to hear any source at all. The rap over the main Wily theme worked especially well, though. Synths were a little thin, could have used something more complex.
UMADEON, BRO?: I was pleasantly surprised by this one. Really nice soundscape and mostly good instrumentation (not a fan of the lead from 0:52-1:17), good job of arranging the sources liberally but recognizably. Transition at 1:37 is pretty glaring, and it's a little chaotic overall, but that's about my only criticism.
My Castle is Burning Down: Props for using Duo as a primary source, you're the first to make heavy use of it so far. Too bad it came at the expense of Flame Man. I like the energy and the bass.
Amnesia: Does everything that Gario does well, but I have a nagging feeling you were struggling for inspiration a little with this one. Nothing I can really put my finger on.
Third Wave Roboethics: Really meshes those three themes together, over, on top of, and through each other. Classic Lemon chips over some nice pads. Really good work here, although there are a couple of off harmonies.
In Everlasting Pieces: Funny that you decided to go with this style, we got several chippy tunes in a row. But you held your own even in the wake of Gario and Hylian Lemon, I think. Nice use of all three themes, excellent solo at the end. A bit short, but what you have is really good.