...I find it funny that the easy levels are the ones that you've ended up making last. I have a sneaking suspicion that good easy levels are harder for some people to make...
That is part of it, but I also decided to deliberately keep some early slots open, so that if needed, I can use them to add tutorial levels for tricks used in some of the harder levels. There's also some degree of leniency here - several early-Loopy levels would work just as well in late-Sane, so I can always move things around a bit if I do end up making another harder level.
Anyway, I've got two sets of replays back from testers now - one covering all of Manic and Delirious, and one covering half of Manic + all of Delirious. I haven't watched the latter yet (a bit burnt out, will check them later today), but the former alone has unearthed 9 backroutes, two borderline cases, and three (non-backroute) new alternate solutions; plus a graphical oddity in one level.
I likely won't get around to making any fixes until a bit later in the week, though - likely to have some busy days coming up, plus there's little point rushing since I'll need to wait until the current contest ends anyway.