Thanks for the comments, guys.
First off, thank you for taking the time to play through my pack and post replays and suggestions. Your feedback is very useful!
Just a few initial responses to your comments as I thought there were one or two points worth discussing:
Played through it and attached my replays in a zip file. 
I don't think you've made a replay collection with your intended solutions though, as there is an impossible level in here: Crazy 11. It's impossible as the hatch which should be possible to save just walks out of the level as all level sides are deadly in NeoLemmix. Letting the right hatch spawn to the left side instead of the right fixes it.
Definitly make a replay collection of your own to maintain the pack! This way by doing a quick mass replay check you can always confirm solvability and also never forget solutions to levels (yes this happens quite a bit
).
Good shout, I'll definitely get on this as soon as I have time. And yes, I'll remember to include replays in future packs. I'll also update Crazy 11 for NL and re-post the pack (I originally playtested it in SL, which allows the Lemming to bounce off the edge).
The Tame levels in the original were quite boring and simply swapping exit and entrance while keeping the 20 of everything skillset doesn't improve the formular by much. Some require just 1-3 skills. There is even a level now which doesn't need any input of the player at all to solve it (Tame 13). Maybe even consider leaving that one out completely (or make some terrain changes).
In general making these original Tame levels any interesting at all without changing the terrain layout is quite a challenge in itself, they really weren't that well desgined.
Speaking of Tame 13 --> Wicked 01 could also some changes. 
I know with levels like Crazy 1, it's a little hard to come up with imaginative solutions. To be honest I would be pretty stumped on how to make this one any better.
Like IchoTolot said above, don't be afraid to add terrain to the level to make them better solutions overall. As long as the level is still the level we recognise, we're not going to complain honest!
As mentioned in my original post, I considered adding terrain to many of the levels to make them more interesting, but I went with the decision to only add/change terrain if needed to make a level
possible (with only very few exceptions).
To be fair, one of the main reasons I went with a remix pack for my first pack was because it's a good way of easing into creating levels (plus I like Colorful Arty's game and felt like a sequel was in order!). I agree it could be better, and I probably will revisit it at some point. For now though, I think my Lemmings time is best spent playing through other people's packs for inspiration, as you've suggested, and concentrating on future projects.
Incidentally, what did you think of the Havoc levels? By this point, I was used to using the editor and coming up with solutions, I think the last 4 in particular are amongst the best levels in there. It would be helpful to know which levels you thought were good so I know what I'm doing right as well as what I'm doing wrong.
Also, when I played through
Reverse Lemmings I quite enjoyed the fact that some of the more difficult levels in the original became ridiculously easy in the reverse version! Wicked 13 is a great example of this. I realise that you don't have to actually do anything, but I think that's part of the fun of it. For this reason, I'm leaving these levels as they are. I think I did a good job of coming up with interesting puzzles elsewhere in the pack, so it's nice to have the odd level where you can just sit back and let them pour into the exit!

Also, I bet ~90% of all the time limits here can be culled in favor of infinite time. Time limits in general only make sense to enforce multitasking in form that multiple lemmings do different parts of the route simultaniously or to block unwanted backroutes that need a longer time.
Here they now just have the potential to annoy the player like: "Oh, guess I have to rewind again and release the crowd 10 seconds earlier." And yes I had quite a few of those moments here. 
So I would throw out most of the timers and have infinite ones instead.
I'm not sure I agree with this. Remembering to release the crowd is often part of the solution... I guess in NeoLemmix it's a moot point because it's so easy to rewind and redo things, so I guess it just becomes an annoyance. I'm open to discussion on this point, certainly, but I'm probably more old-school on this - I prefer having to remember to click that increase button at the right time, as part of the puzzle!
Quite a bunch of levels always use the same trick for crowd containing: The digger pit. Switching it up a bit more can make these levels less repetitive.
Really? I thought I switched it up quite a lot... I'll play through them again to do the replays and see if I get the same impression. Off the top of my head, I'm aware of at least 8 crowd-containing tactics which I employed throughout the game:
1 Digger pits, obviously
2 Bashing/mining in opposite directions and then building
3 Using 3 builders to make a "blocker"
4 1 Lemming climbs out of an existing pit
5 Building up to a wall and having the last Lemming to walk over the edge of the built bridge bash through the wall before the builder closes the gap (it's difficult to employ this one but I managed it a few times!)
6 Having a Lemming mine/dig through a built bridge so that the builder carries on alone
7 Not containing the crowd at all!
8 Last but certainly not least...the solution to Havoc 19 (which requires 4 skills and perfect timing to contain and release the crowd)! I was particularly proud of this one!
Having said that, I'm more than interested to learn more containing tricks (as long as they don't involve using glitches) for inclusion in my future levels, for sure! Also, since there are a lot of levels in this pack and I worked on them one after the other, I'm aware that some of them may have been a little bit rushed in this department.
Anyways, I'm really glad people are playing through this pack. For now I'm much more interested in finishing up my current project, which I hope you'll agree is much better. But, I will look at revisiting this (and maybe even the original
Reverse Lemmings, if Colorful Arty is happy for me to do so) in the future to make a more definitive version based on people's feedback (and what I learn along the way...)

Thanks again guys, keep the useful comments coming! Constructive criticism, helpful feedback, and genuine encouragement are always welcome.
I'll let you know how I get on with your level packs in the meantime!
Best regards,
-WillLem
