I think historically, one of the considerations for ditching direct drop in modern engines was that it had the tendency to cause backroutes in custom levels. There isn't really much of a reason for level designers to use direct drop as a feature, so with the backroute consideration it's more of a nuisance.

Regarding your table of where it works, isn't there at least some engine where direct drop only works if the exit trigger area is on terrain (so the lemmings go home instead of splatting, but they would fall through an exit that's in mid-air)? So I think it's more nuanced than "it either works or it doesn't".

2) If falling lems can interact with traps, water, fire and other objects, then they should also be allowed to interact with exits. Any ports/engines/clones which feature one behaviour and not the other are therefore inconsistent.

Comparing permanent traps (like fire and water) to exits in this context feels like comparing apples and oranges. Many triggered trap on the other hand are quite similar.
Should triggered traps allow for direct drop? Arguably that depends on the design of the trap. For example, it makes sense for the ONML rock chameleon to catch lemmings in mid-air. It makes little sense for the 10-ton trap to squish lemmings in mid-air. Even without exits in the mix, you have to make a call which will feel weird for some traps (unless you want to introduce different trap types, which would be a whole new rabbit hole...).

Thanks for playing! Notes on your solutions:

Day Care Center:
Undercut:
Cellar Dwellers:
Construction Site Conundrum:
Btw, if you have suggestions for re-ranking levels, I wasn't confident in my original ordering so I'm happy to shuffle things around a bit.

If you look at Lemmings 2 DOS version, you'll see there's a levels folder with one file for each of the 120 levels plus the 4 practice levels. After decompressing these files, you can read the level layout of each (as documented in the file format description).

The L2 level/style format has been long known (see here - note that you'll have to decompress the levels/styles first using lem2zip, which you can also find there). The challenge will be that the levels are defined as a grid of 16x8 tiles, while (from what I understand) the existing NL L2 tilesets use pieces that are usually composed of multiple of such tiles. The L2 style definitions do define such pieces in terms of the smaller 16x8 tiles, however, I don't know if the NL L2 tilesets were created in a systematic way reflecting these definitions, or just ad-hoc.

All the L2 graphics (both 16x8 tiles and the composed pieces) have been ripped long time ago: https://www.lemmingsforums.net/index.php?topic=6588.msg102252#new

A slightly ugly way would be to write a script to create 12 new tilesets where all the tiles are of size 16x8 (you could use the ripped graphics as input), and then write another script that converts L2 levels into NL levels using these 12 tilesets, automatically creating the terrain and object placements (assuming the existing NL tilesets are consistent with the L2 ordering of objects, otherwise you either have to manually create a mapping between the two, or extend the first script to also generate the NL objects -- I don't know how NL would deal with fling objects and the chain and cannon though). The skillset you'll have to tweak manually either way as I guess you don't support the full palette of L2 skills.

It's finally time for me to release the Lix levels that I have created over the years. Some of them are brand new, some of them are over a decade old, but better late than never. They are part of the latest Lix download in the level folder single/geoo!

The pack has 5 ranks, which are more like themes. Each rank is independent, and you can play the ranks in any order and freely skip between them. Within a rank, I recommend playing the levels in order.

• wrappy: Levels that make use of the horizontal and/or vertical wrapping. It turns out that even in single player, wrapping is more than a gimmick and gives rise to a lot of interesting ideas! If you only ever play one rank from this pack, this should be the one. The majority of these use 5 skills or less, but even a 3 skill level may stump you for a little bit here. These turn out to be primarily logic puzzles with very easy execution, except for maybe the last few.
• flowy: These levels make use of dynamic crowd control: stalling, redirecting, merging crowds without fully blocking them off. These levels require thinking about when things happen as much as where, and a lot of skill placements will be unintuitive, initially. Due to the nature of this, some levels may require a bit of trial and error to find the placements, but I tried to make execution as easy as possible, and the replay tweaker should help as well. Note: 4 of these levels are also featured in the lemforum pack, but I replicated them here for the purpose of the level progression.
• classy: More traditional and often larger levels with more skills where you need to figure out the skill placements.
• loony: Many of these revolve around some physics quirks or some other quirky idea. A good portion of these keep it very simple, though some of the later ones may end up taking some work to get the execution right.
• sketchy: This is where you find the levels that didn't really work out. Many of these may have some interesting underlying ideas, but somehow these ideas didn't translate into good levels. Feel free to skip this one.

The ranks are not sorted by difficulty, but rather by how interesting and fun I perceive the levels to be. Within wrappy, flowy and loony, the levels are ordered to create a level progression that gradually introduces and explores different ideas. This only loosely corresponds to actual difficulty of the level, but each of these ranks starts out gently. Classy and sketchy are sorted by how I estimate their difficulty, which may be different from how difficult.


I may add and shuffle levels in the future, so posterity, please refer to levels by their name rather than rank/number, as the number within a rank is likely to change in the future.

Thanks to Simon for playtesting, and Ramon for playing some of these during the races with Simon! The levels are part of the official lix release as of version v0.10.21 (for about a month already, so about time I make this topic), and can be found in single/geoo.

I'd be very happy to hear everyone's feedback and see your streams, videos or replays!


Just Mine (wrappy): This map wraps horizontally. Why do you have three miners here when it looks like two are enough? Play this level to find out and wish you had four miners!


Humpy Bump (wrappy): This map wraps horizontally. How can you safely build a bridge when lix are walking around everywhere?


Pommes Schranke (flowy): How do you fit your sausage (that comes with fries, ketchup and mayo) on a plate that's too small for it?


Roots of Life (flowy): Even though this level has only 5 skills, it stumped Ramon and Simon for almost an hour!


Bathroom Break (classy): Hurry before everyone else arrives!


Filter, Map, Fold (loony): The typical (functional) pipeline of reducing data to a single (summary) value. Can you do the same to this crowd of lix?

I remember having that issue back in the day when I first played Cheapo (which may have even introduced this behavior? Or was it in WinLemm too?) It confused the heck out of me, and it took me a while to understand what was going on. I thought it was a bug and restarted the game in order to restart levels.
At the same time, it's way too useful of a feature to disable by default (thereby making it extremely hard to discover).

I'm surprised that clicking the R does not cancel the replay, having that would be a good start at least (especially if the R sufficiently stands out visually). I think realistically what Lix is doing by displaying some text is a decent solution. It's slightly inelegant, but at least should leave no room for confusion.

Hah, sure! Do you happen to be free at that time? (Of course, unless Simon wants to have a chill stream.)

Otherwise I can also see how far Simon makes it, and then compile a level progression from those levels that Simon hasn't played for you to race

Saturday would work great for me. Sunday I got some other plans already.