Thanks, IchoTolot!
I'm relieved to say that there are barely any backroutes among these, and generally much fewer than I anticipated! Given that you seem to be the first person who plays the Rockstar levels (and also one of our most skilled level solvers), I believe that's a good sign!
Disclaimer: I generally don't consider a level backrouted if a) the player got close to the intended solution, but was just slightly more efficient in skill use than me, i.e. has a couple of leftover skills that don't really matter all too much in the grand scheme of things, or b) a player does find a completely different route than the intended one, but still uses all or almost all of the skills (that is what I call a valid alternative solution, because it still arose from and is subject to the same restrictions, in terms of terrain and skills provided, as the intended solution).
With this set of criteria (some may be stricter about enforcing their intended solutions), there are only two backroutes in the Rockstar rank: One minor one which could still also qualify as an alternative solution, if I didn't like the intended solution so much that I do feel the need to enforce it
. That's on the level "Highway to Hell". Containing the crowd shouldn't be quite as easy as it was for you, but this is something a little steel can solve.
The second backroute, which is a more severe one, was on "Under bergets rot". The lemmings are still supposed to go through the mountain, not around it on the outside. Typical case of the Stoner being overpowered again. I still have to think about how I can fix this.
At the moment, you seem to be solving these levels faster than I can fix them, even if there are only few that I need to fix
... so prepare for one major update sometime soon, instead of several minor ones. I do want to add some further recoloured sprites to some of the geography levels, as well as expanding the pre-level hints on the Noisemaker rank a little to make them fulfil their purpose as tutorial levels for these tricks a little more (since this was one criticism you correctly brought up). Especially "Glide and joy" and "Rock, paper, scissors" can end up being unintentional roadblocks for newer players, because the hints the pre-level texts give about the tricks to be used here are too vague.
The pre-level texts are of course also going to be changed in the Old-Formats version (which I continue to maintain for the sake of the Radiation and Slowfreeze levels in their original form). The sprite recolouring, meanwhile, of course will only happen in New Formats.