My latest level has now brought every rank up to a double-digit amount of levels. It's also put the pack overall just one level away from half way to completion!
"Sharp Minded Lemming"
20 lemmings, save 18
Release rate 50, no time limit
1 Glider, 1 Bomber, 1 Blocker, 3 Builders, 1 Basher, 1 Miner, 1 Digger
It's also probably the first somewhat-easy level I've made that I feel suits the abstract1 track (yeah, I know Blissful 5 "Stars In Their Eyes" of LPV had that track, but this was almost solely because I wanted the first 8 levels to introduce all 8 standard tracks). On top of that, it's also the first level I've used the newly-supported one-way-up arrows in, although their purpose on this level is almost purely decorative; and IIRC it's also the first level I've made that uses the "Rotate" flag on an object (notice the sideways water at the edges of the levels, which again, is pretty much pure decoration as the sides of the levels would kill the lemmings anyway, and you'd have to go out of your way to reach them).