Let's try to find all the official game levels with likely backroutes...

[Mr. K]

Levels which most likely intentionally have multiple solutions, for example Tricky 9 "They Just Keep On Coming", shouldn't be counted as backroutes. However, when the intention of multiple solutions is questionable, assume the worst.

I'm mostly only aware of backroutes in Lemmings 3D. Ask if you want to know the details of any of them.

Original Lemmings
Tricky 19 - Postcard From Lemmingland
Tricky 25 - Cascade
Tricky 30 - The Crankshaft
Taxing 4 - Lend A Helping Hand
Taxing 6 - Compression Method 1
Taxing 22 - Come On Over To My Place
Mayhem 24 - All Or Nothing (Versions with arrow key support only )
Mayhem 29 - Save Me! (I heard you can go to the left at the start... correct me if I'm wrong)

Lemmings 2 - The Tribes
Egyptian 6 - RUPER'Z QUESTLING
Medieval 3 - ALL IN A KNIGHTS WORK!!
Outdoor 5
Shadow 6

Lemmings 3D
Fun 8 - Lemmings Inside
Tricky 25 - Breakout
Tricky 32 - Dot to Dot
Taxing 41 - Spaghetti Junction
Taxing 57 - T Minus Five And Counting (?)
Taxing 59 - Lemmtris
Taxing 60 - Death Slide
Mayhem 63 - Tower of Lemlab
Mayhem 66 - Family Tree
Mayhem 74 - Jelly Belly Islands
Mayhem 78 - Castle Peralus
Mayhem 80 - Final Maze

Lemmings Revolution
Unknown name. Click here for pic showing backroute.

[AAA]

In Taxing 4 of the original Lemmings, You can bash under the metal to get outside the intended play area. You have enough builders to make a bridge network to get you to the walls of the exit room, which you bash through, and get your lemmings to safety without having to deal with those annoying spike traps.

[Mr. K]

Alright. Any more that you post, I'll add to the list up there. Does anyone have the name of that Revolution level on hand, btw?

[nobody]

You can bash through the ceiling in stepping stones (Mayhem 17 I believe) and you can dig and bash through the floor under the columns in Taxing 1.

[nobody]

I've also heard stories of people going underneath the bowl of soup in Mayhem 14 but I've never seen it pulled off.

[Mr. K]

Isn't that the intended solution for Taxing 1? I never found any other way to do it...

[nobody]

I think the intended solution was to bash through the first two columns and mine through the third. Either way, one of the is the intended solution and the other is a backroute.

[nobody]

Here's a couple more for Lemmings 2:
Outdoor 5 - Rope up to the ceiling underneath the exit and use your club bashers to get through
Shadow 6 - Rope up to the roof of the first house then rope up to the wall and fence through to the exit

[DrLemmingsham]

Alright. Any more that you post, I'll add to the list up there. Does anyone have the name of that Revolution level on hand, btw?

I have the name of the Revolution level. It's called "Watch out! Evil about!"

[Mike Rosoft]

Let's see.

I already know about the backroutes for Cascade (Tricky 25), If at first you don't succeed (Taxing 1), Compression Method 1 (Taxing 6), and Come on over to my place (Taxing 22). Other unorthodox solutions I have managed to do include:

*Upsidedown World (Taxing 13), saved 100%. On the right, I needed to keep two lemmings busy while making sure that the rest of the tribe can't escape to the right, but can escape to the left; I had to spend a digger, a miner, and only one builder. I followed it by bashing under the one-way hill in the wrong direction, sending a climber over the next hill, breaking into the bridge construction so that the climber can't escape to the right, going under (rather than over) the trap (while making sure that I don't have to spend the second builder to stop the basher) ...
*Walk the web rope (Taxing 20), saved 100%. Not too much of a backroute, really. The key to the perfect solution was to start bashing on the right and stopping the basher before he completed a single stroke; afterwards, I had to close the resulting chamber using stairs so that lemmings can enter it but can't escape.


Mike Rosoft

[siergiej]

Fun 22 (A beast of a level):
You can build some stairs to the upper part of the trees and then bash the way near the upper border of the level.

Fun 29 (worra lorra lemmings):
You can go this way

Not practical, but funny

I will add some other solutions later, as I don't remember them now

[insulfrog]

(Original Lemmings) On Taxing 1 (harder version of Fun 15), you can dig under the 3 pillars by digging/mining a few pixels and then bashing.  Then after you bashed under the last set of steps of the last pillar, build up.

[QBeez]

Mayhem 17 (Stepping Stones): You can go over the top.

[Clam]

I notice nobody has mentioned ONML yet, so...

Wicked 14 (The Lemming Learning Curve): You can go through the chains and the girder to the right of the upper platform. I managed to get 100% this way (though possible the usual way too).

These backroutes don't have to be easier than the intended solutions, do they?

[BBP]

(Edit: Sorry, I'll read the entire thread in future.)

In Lemmings Revolution you can exploit the Blocker Relive bug, with which you can revive a blocker. Click on Bomb and, as he cowers prior to exploding, let him build, bash, mine or dig, depending on your supplies.

In Nice Shooting Tex you can save yourself some tricky things by reviving the blocker at the bottom level.
-There'll be no need to turn the lemming building the stairs into a blocker, so you can use the extra block for precision bombing in the top Lem section.
-By saving the blocker, you don't have to turn one of the 5 Lems falling through the counter block in a floater, which will also save you a basher AND a builder (which you can use to revive the blocker). The level will also be much, MUCH less tight on timing.