Worldpeace, these songs are incredible. Each song seems to be able to fit multiple themes, sound natural, but most of them seem rather tense. I can't really complain, since that's the style I like.
11 is a pretty calm song, and I can see it being used in dark, quiet levels, such as starlit paths, forests, and easy caves.
20 can fit into any tough situation, so it seems best for places where you need extreme caution and/or fast pacing in order to win.
21 seems to be fit levels the same way as 20, only more upbeat and catchy. I'm pretty fond of this song, though it's quite short. If it's your own song and if you don't mind going back to tweak it, have the song loop twice then add a longer segment that it can flow into easily. You seem really good at that.
22 is my favorite song you have, by far. This would be absolutely perfect for a sky level. Don't change this one! >.<
24 is a great utility song as well for tense levels of all kinds.
25 is the one you used in that video. This one is extremely memorable. It's not super-tense, and I can see it being used just about anywhere, from puzzle rooms to normal level segments to perhaps even mini-bosses. This is my second favorite, close to 22.
28 is very different from the rest of them and seems more like a boss song. I really like this one, too.
29... I can't really say because the SPC didn't work when I downloaded it.
Are these your own creations, or conversions? Either way, you have incredible skill, because these songs are beautifully done. Perhaps you should wait to submit them, though, since those songs set your hack apart from others, but we would be happy to have them here as well. The songs are far above average, especially 22, which is simply... amazing. In spite or our million-and-one songs, there aren't a lot of multipurpose or high-tension songs, so your songs bring something completely new to the table.
Now, let me comment on your video... That level seems like you've been working on it for a very long time, and it's thoroughly thought out. It looks extremely challenging, and seems to put a lot of SMW's puzzle elements together into such a small space. We don't have many puzzle-themed hacks, and judging by Keytastrophe's rating, puzzle hacks are received well here, and I'm sure you already have quite a few people eager to play yours, even though you only got here a couple days ago.
Overall, as a SMW hacker and a music hacker, you are patient and talented. You seem to put a lot of time into everything, and it shows.
Yes, S.N.N. composes a lot of his own music, and there are a few others that also compose, but 95% of the time, we convert songs from MIDIs that already exist, since it's faster and appeals to more people's interests. (What I mean is, more often than not, people will be seeking Mario music, Final Fantasy, Secret of Mana, Kirby, etc. rather than homemade songs, and to meet that demand, those are the songs we work on.)
Oh, and welcome to the community.
Just look above you...
If it's something that can be stopped, then just try to stop it!