Purchaseable cheat codes prolly. Dunno how they work really, but that sounds like it's possible.
Or he just cheatengined some marines health to never drop down and then used them to murderize everything.
Nope, I did
everything through Cheat Engine, and nope, I didn't hack their health. It takes a while to set up the chapter on a new game, but I have already described the basic steps in my previous post. Just to reiterate:
-Have Slow and Purposeful for survivability
-Give everyone either Artificier or Tartaros armors plus Rosariuses.
-For assault marines also give Storm Shields for further survivability.
-Raid, Raid, Raid. While normal battles through Attack are good against Orks because of their vehicle-bug (most of the time, at rampant they get Tank-bustas that chew through your Predators like tissue-paper), raids are infinitely safer against everything else if you have the above-mentioned army because the enemy also doesn't have access to vehicles and heavy units, meaning they cannot deal enough damage to break through the armor of your marines. I have beaten Rampant Tyranid armies with this without suffering a single
injury.
-If all else fails, Bombard. It is especially useful on already devastated worlds where there would be no civilian casualties. My last playthrough started with something like ten such systems controlled by tyranids. It's also fun to see colonists retake them later, though it may take years after you are done with them.
On top of that having the right STC upgrades also helps. Here's how to get them:
-Get an STC fragment.
-Save
-In CE, search for 1, type:Double
-Spend it. It will either give you a Gear, Vehicle or Ship point. Take note of this, as there are actually a different type of STC for each type that are stored separately.
-Now search for 0. If you are lucky there are only going to be a few addresses. If you are really lucky, there might be only one. You are probably not going to get lucky though, so here's a tip: Look for an outlying address, usually that's the one.
-If you can't find it at all, reload your save and start from the beginning. The game recalculates all addresses on loading.
-Once you have the address, set it to 10 and save to a different slot.
-Now go max out that particular upgrade type. If you don't like the random upgrades, reload and try again until you get what you want (I personally always go for armor/survival upgrades)
Note that since there are three different types of STCs, you have to do this three times to max out everything. It's worth it though.