Answers I can give, ~2h of play time.
If you're able, well you be ripping/recording and uploading the soundtrack?
Nope sorry.
What aspect of the game has held your interest for the longest?
Octo Valley, lel. Can't play online, and can't test Battle Dojo.
Is the single-player enjoyable enough on its own? Or does the game rely on strong online mp presence?
I've just cleared the World 2, the entire campaign seems consistent enough. The Mario Galaxy vibe is really nice.
It's not very difficult though, but it does a good job teaching and getting you used to the mechanics of the game.
Bosses are really funny to fight, and they look so stupid lmao.
If you have played online, how many levels you grew up and in how many matches?
Are you having a lot of fun?
Can't play online sadly.
I enjoy playing Octo Valley so far, it's not super amazing for now though, hope it gets better and better.
Can you play on the reviewers' server and post in the prelaunch splatoon miiverse community?
Nope and nope.
Can't even post or see anything from the Miiverse community of the game.