Off top of my head I remember these levels where running out of time is a common mode of failure for many:
- Just a Minute (both part 1 and part 2)
- The Fast Food Kitchen
- We All Fall Down (Taxing and Mayhem)
- Heaven Can Wait (We Hope)
- The Crossroads
Some more examples of tight time-limits in the original game:
Every Lemming For Himself
The Ascending Pillar Scenario
Hunt The Nessy
To add to your list and ccexplore's:
The Crankshaft Besides
Tightrope City, probably the first level with a time crunch, although that should go to
Heaven Can Wait. Not a problem if you send multiple climbers, but time was usually a problem only because I kept sending one worker. Even with this, I think I would always have about 30 seconds or so left, so maybe not too much of a problem despite that time can be tight.
If at First You Don't Succeed I guess it depends on the solution you use, but generally I would release the crowd when the worker lemming finishes building over the last gap. When I dig under the pillars, the lemmings would have a long way to walk back and forth in the pit, and so I would have anywhere from a second left to a few seconds remaining.
Mary Poppins Land The timer was a huge problem only because I have always used the solution of sending only one worker lemming instead of two. If using my solution, when releasing the crowd, it has to be done before the second splatform to the diagonal platform is done in order to still have enough time to pass. If I remember correctly, they have to be released by the 40 seconds mark.
Take a Running Jump I usually use the solution of making a splatform, and if my memory serves me correctly, you need to up the release rate a bit before the timer reaches the 2 minute mark. The lemmings do have a lot of walking to do in this solution and so the timing can be tight.
One Way or Another I've always taken the route on the right. I think I usually release the crowd by the time the last gap is built over and it's usually about 20 seconds or so left. I don't remember the skillset, and so I'm not sure if the left route is possible, but if it is I would imagine that it's way more time consuming since they have much farther to walk.
The Far Side At least if you do the normal solution of going around, because I do believe there's a video where it's possible to bash the top on Dos and therefore time will not be an issue. Almost every time I play this level, I release the crowd as soon as the worker lemming seals the hole with the wall on the right or possibly even when the worker lemming seals the gap going to the left after already sealing it to the right and I think I would finish the level anywhere from just a second to 10 seconds left. In other words, I think as long as you release the crowd by a minute left or even 55 seconds left then you'll still pass.
Pea Soup Surprisingly, this can be a time cruncher. At the same time, not too difficult to see this, since pretty much the entire level is spent building really long bridges. I think I usually release the crowd by the time the worker lemming falls off the right side of the bowl, i.e, when the worker hits the floor where the exit is, and usually will have about 10 or so seconds left.
Save Me Maybe not that big of a problem on time despite that it can be tight, but it at least was for me when I was a child. There have been times when I have released the crowd too late.
From ONML, a lot of them. In Crazy, I say the most notable were
Digging for Victory and
No Problem, and I guess
The Stack,
Keep on Trucking,
ON the Antarctic Coast, and
Rocky VI can be too. For Wild, definitely
Onward and Upward. Also
It's a Tight Fit and
Snow Joke and
Lemmingdelica. For Wicked,
Rocky Road,
Spam, Spam, Spam, Egg and Lemming, and
Up, Down, or Round and Round (only because I always up the release rate after bashing through the two pillars at the bottom). Finally, for Havoc, definitely
Welcome to the Party, Pal, but I say other notable ones are
Race Against the Cliches,
Lemming About Town (at least when the climber gets to the top, as it apparently always does on Dos despite the bridge being at the edge),
Synchronised Lemming, and
Where Lemmings Dare.
edit: Forgot
Lemmings in a Situation too.