I’ve done it. As others have mentioned, you weren’t on a Destructive map.
On a Destructive map, you lose 20% of your current health every time an enemy attacks. To elaborate on the rules of this, even if you don’t take any other damage, when this constant multiplication by 80% takes your Trimp HP below one, the stack dies.
So you have to both get your block up high enough to never take direct damage, AND get your damage output up enough to kill your enemies quickly.
I’m not totally sure about the color scheme, but as far as I’m aware achievements don’t become permanently unobtainable. I think they change color from yellow to red when you can no longer obtain them in your current run, but will go yellow again when you portal.
You can always replace a modifier with another one, but it costs six times the heirloom’s worth.
If you happen to have an heirloom with an empty slot, you can add your choice of modifier for ‘just’ 2x, rather than the 6x replacement cost.
Yeah, I’ve gotten heirloom’s with an empty slot. I thought, “what do I need that for?” and recycled 'em. 
I was also poking around the FAQ and discovered there are levels of heirlooms beyond rare, so it’s probably early to think about upgrading too much.
Another question: I’m doing the Electricity challenge but am also thinking about trying to go for Z100, so would I get more helium by doing my Void maps at Z79 and letting them double, or get more helium by waiting for Z100?
Z100. Base, unmodified He for a void map at Z79 is 17752. Base, unmodified He for a void map at Z100 is 39482. Plus you’re two whole brackets higher on the heirloom table.
But if you’re doing the electricity challenge, you get an additional 1.5 times the helium after completion. So that would be 44380 at 79.
Plus, it will be much easier at 79 than 100. Might be too tough at the limits of a run. I’ve had to abandon void maps after leaving it too late.
Are those numbers correct? I’ve done void maps at 80, and didn’t get anywhere near 17752. What are the modifiers reducing it?
I just portalled and I was kicking ass, looking like I was going to finally get The Block cleared in under an hour… then I realized I was doing the Scientist II challenge and got totally hosed on all those Snimps and Gorillimps… spent more than an hour on just the second half of The Block map
The only challenge I ever totally hosed up was the first Scientist challenge. Didn’t read the instructions.
Soon as I make Z90 I’ll unlock Scientist III.
Yeah, I was following the guide, so I knew I’d get there eventually but chipping away at those Snimps with barely enough Blk + Health was tedious. Definitely not for the speed runs!
Ugh, yep, I screwed up and used the wrong column from here. That’s the sum total to that point column, not the single level.
So, void maps are double the Improbability of the zone, and also I should have double-checked levdrakon’s mention that Electricity doubled Helium, you’re right that’s a total of +150% rather than doubling.
So… showing more of my work this time so you all can see any remaining errors, per the wiki L79 Improbability is 437 He while L100 is 591. In run, doubling for void maps would mean that L79 Electricity is 437 x 2 x 2.5 = 2185 He while L100 would be 591 x 2 = 1182 He.
It’s still true that heirloom drops in the 60-79 bracket average a lot worse than those in the 100-124 bracket, which may also be a factor in the decision.
Actually, I checked too and it’s 2.5 times the helium. I went ahead and did them, but now I have another void. 
It took 4 days to get to Z80. I’m thinking that’s too slow, so I think I’m just going to go to Z90, unlock that challenge and do it some more. Once I get to Z100 and unlock dailies, it would be nice if I could actually do a daily in one day.
Dailies are really awesome, now more than half of my HE has come from them. Since you can decide the zone to end the daily on, you can always finish in a day
They’re only the second best part of Z100, though: Frugal is a total game-changer. At Z90 it would multiply your base type production by more than a factor of six.
You’re right that 4 days to 80 is still probably too slow to get to Z100. Something to look forward to, though.
I put some He into Agility, which makes the clock run faster, so all that slogging gets done a lot quicker. The first 40-50 levels took maybe an hour.
I still can’t clear Trimple of Doom in less than an hour, so not fast enough yet. I have 8 on Agility. I’ll just run Electricity some more.
Agility maxed out is 2626 He - seems like a quality of life expenditure that I’m happy to pay.
I finally got Trimple of Doom down under an hour a few days ago, and also got the Prison down to 5:35 so that was a really nice run. Getting through that under four hours still seems quite impossible, however.
Yeah yeah, just let me do Electricity 10 more times.
Electricity 10 more times? I’m still working on my first time. I re-specced after spending forever on zone 65, but even with birth rate almost at the point of being instantaneous, I’m still slogging in the upper 60s.
I’ve not done an Electricity. Is it worth it?
I’m currently doing my third Daily. Looks like you get a lot more bonus with less or the same effort.