Make the first 4 lemmings floaters. When the first one hits the ground on the bottom level make him a blocker to turn the other three round.
Make lemming 6 a blocker as soon as he lands from the exit, up the release rate to 99
Make lemmings 2&3 into climbers.
Set lemming 4 bridging as soon as he turns around from the lemming 1 blocker.
Make lemming 2 an exploder while he's climbing up the wall to the right: about when his head is level with the top of the exit.
Lemming 3 climbs into the crevice the explosion made; make him bridge to the left just before he falls back down to the bottom level. When his bridge is half complete, make lemming 6 (the blocker) an exploder.
Explode the other blocker on the bottom level. The two bridges should stop the other lemmings dying of height.

What is your time on Tricky 07?  (just curious...)

I have a partial solution that might explain how Fun 09 in 36 seconds is possible, but I can't figure out how to finish it.  It's very tricky:

1. Make the third lemming dig as soon as he hits the ground (you can make the first dig if you want, but I've found this way helps with the precision clicking coming up)
2. About 10 lemmings will escape the pit being dug, and the first two will be a little ahead.
3. What you need to do is turn most of the lemmings back, but have at least two lemmings drop down below (one to bridge the trap, one to bridge the final gap by the exit).
4. If you have two diggers either side of a blocker (this really needs to be pixel-perfect) they will free the blocker, but their pits will be separated by a small column of terrain.
5. Of the two lemmings slightly ahead of the other escapees, wait until they have just passed over the trap beneath them, then make the second one of them a blocker; then immediately make the first one a digger. (This is why the slight gap is useful, the lemming ahead is already in the right place to dig; and if there's no gap then an extra lemming will escape the blocker. If you do it the other way round then you have to worry about not digging too early so that you free the blocker you just placed.)
6. This is the hard part. You want the final lemming that escaped the pit to dig the exact instant he turns round from the blocker. If done right this will free the blocker and he will walk into the pit that the lemming further ahead is digging, and this pit will be too deep for him to escape.
7. With this timing, the first pit should finish with the two lemmings facing in opposite directions. Leave it as late as you can to make them floaters; and make the digger that freed the blocker a floater as soon as possible. You want to leave the two lemmings that hit the floor as much of a headstart as possible.
8. The lemming that heads left towards the trap should bridge the trap as late as possible (this is the part I haven't got to work yet, I'm not fully sure it's possible) He needs to have built up to the wall before the other digger drops down and walks over the bridge (he'll turn round due to the wall and get killed by the trap through the bridge)
9. As soon as the bridge over the trap is done, immediately bash the digger who's digging down the main body of lemmings. They'll drop onto the bridge and all head towards the portal.
10. The lemming who headed right should bridge the gap to the exit as you'd expect.
11. If all is done right the other 49 lemmings will catch up with him just as he finishes bridging and exit in around 67 seconds.

Notes:
- freeing the blocker needs to be perfectly timed. Even when I know when to dig I still mess it up 9 out of 10 times.
- it is possible (and perhaps easier to time) to free the blocker with the second digger still facing right. However this means you'll get two lemmings facing right; and as the first lemming has more bridging to do before safety compared to the lemming bridging the trap, I don't think this is the right way to do it.
- if you look at the terrain right at the start; just before the steel there are three long ovals in it. If you set off a digger near the right hand side of the first oval, his pit will contain an overhang sticking out from the right hand side. I don't know if this is helpful in any way. It seems (it's happened twice for me) that if you dig in a certain spot, the overhang will be the right size so that there's a large enough gap in the ground for him to stop digging; but he will step onto the overhang and hence turn right before dropping down. I can't see how to get this to help, but I figured it was interesting enough to mention.
- if you follow my method above you'll have one digger left over. I can't see a way of using that to slow down the third lemming that hits the ground by the trap. I've tried making the blocker start digging as soon as he is freed (before he drops into the pit being dug to his right) but it doesn't slow him down enough.

Yeah the Lose X numbers are based on the total lems including cloned ones.

I've just checked the Mayhem 10 EU leaderboards and fifth place has a time of 1:16.14 so they are seperate for each region.

I do wonder if there's a steel glitch, especially with Mayhem 5. I'm 11th but 5th is five minutes faster and even if I maxed my solution it would be nowhere near that time.

Frevett, if you just want 100% on Mayhem 10 then ignore the leaderboards for now. There's a slower but much easier method. Mayhem 4 is interesting and uses some ideas that are quite obscure. No glitches, but you need to be creative with the skills.

One with the main body of lemmings walking across the top all the way, and one with them getting turned back and heading through the portal

dig through the first platform and leave a step for lemmings not to die of height and then get the two blockers close enough together so that one can free the others. Utterly stumped on how to stop lemming 2 escaping the digger though.

Completing this level in 70 seconds or under would require all lemmings to use the teleporter.  I have an idea of how to do this, but I can't actually do it.  A steel-digging glitch may be required to actually pull it off.

Thanks for that. I remember having an idea for Taxing 9 but I couldn't get it to work and assumed it wasn't possible since as you say no-one had done it at the time. I'll have to have another go.

When the trophy patch was announced it was implied that there would be DLC, but I've not seen anything since. The patch was done by Cohort Studios rather than Team17 but there's nothing new on their site either. Hopefully there is something coming still.

I'd be interested to know what you're doing on Mayhem 5. I've saved 100% but my solution was nowhere near the times at the top of the leaderboard so there must be another method.

First lemming to fall into the right hand side climbs up and bridges immediately - bridging 4 steps then blocking. Second lemming into the right climbs up and bridges the gap the lemmings drop through. Third lemming into the right drops through into the compartment just before the bridge piece can be placed blocking him. If you block the first lemming on the third step it doesn't seem possible to free him with a basher. If I could keep the third lemming out of the compartment they can all go into the left compartment and dig down.

I was stuck for ages trying to bridge the lemmings out of one compartment rather than stopping them entering entirely. I managed to bridge them out of the left compartment and into the right one, but was left with two bridges too few for the last part unfortunately