I didn't mean a group of 16 levels, but I didn't word that too well. Round 2.1 to 2.4 as you're doing now, with hopefully 2 survivors apiece.

Looked at the next three levels - I say "looked at" because I only actually solved one of them.

Individual level feedback (click to show/hide)

0221 "Tonight It Is Showtime" - I honestly don't have the faintest clue what I'm meant to be doing here. There doesn't appear to be any way to get a lemming down to the bottom without first using a builder. However, there's no way to get the second builder pickup without using another builder, except by digging straight down, and I can't see any way to safely manage the crowd while doing this other than two digger tunnels, but having them offset like this means falling straight past the pickup. Unless I'm overlooking something that should be obvious, this level is far too hard for the 2nd rank.

0222 "Basher Laboratory GRO" - Yeah, I don't really think using that trick in a setup that requires 11 bashers, with other elements of the solution both before and after it, while requiring it to be done at the right timing, was a good idea. To be honest, I don't really think using that trick at all, outside of maybe a setup that just uses one or two bashers, or in a proof-of-concept level containing nothing but the trick, is a good idea. Aside from one minor element near the end, I could tell how to solve this level as soon as I saw it, but actually executing it was a nightmare. Sorry, but this is by far the worst level in the pack so far.

0223 "Go On, Make Their Day" - This one looks like it probably has a fair and reasonable-for-the-position solution, but I'm a bit burnt out after the last two to try much for now... I'll continue later.

Spoiler (click to show/hide)

2 21: I am actually quite surprised that this level gives you much trouble as currently it has not proven to be a major roadblock and this level actually exists because of a trick I learned from you in one of your early ranked levels. I will judge it after it is solved.

2 22: Intended solution, except the climber just could have done the exit path earlier without having to bash on the steel a few times. How exactly are you executing it that it requires much timing. I simply just assign a basher whenever a lem stands on the most right pixel of the basher mask and that is all that needs to be done to execute it. I think we have different trick preferences here as I was quite impressed with this trick when I saw it in one of Gronkling's levels.
I can at least say that this is the most extend to which you have to use this trick in this pack.

Have you got a replay for the 4 19 one?