I finally double looped Nuclear Throne! When I looped the first time I had a gatling slugger I'd carried through most of the game and a hyper launcher I'd found in the throne room. I had fish with gun warrant, which means I have infinite ammo for the first ten seconds of every level. Might not sound like much but the first ten seconds of a nuclear throne level tends to be the most deadly time. I spent those ten seconds holding down the trigger on my gatling slugger and watching as shotgun fingers caused ludicrous mayhem.
Carried those two guns through the entire next loop, until I got into a crown vault. Decided to take crown of destiny for the free mutation... got fish's water boost throne butt, which while pretty good, is literally the only mutation in the game that could possibly get me killed. Then I realized something terrible, when I used roll even once, I could never stop. I had to water boost everywhere that level, bouncing off of walls and everything.
Activated it in both palace levels because muscle memory is a bitch. Managed to fight my way down a tiny, long hallway that had a sniper on the other end by spamming my hyper launcher down both ends it while somehow dodging everything including the friendly fire.
Get to the boss at 2 health, realize that once you've looped the throne hallway spawns a bunch of pickups. Rush to get them... and roll to go faster, activating water boost. Find out that the red chest spawned a nuke launcher, pick it up. I then proceed to beat the nuclear throne while infinitely water boosting. Hilariously, it was hard to keep the throne onscreen while doing this, and nukes move slowly and follow the mouse. So at one point I was dodging laser spam everywhere while two nukes circled perilously close in front of me. Fun times.
I beat the boss with 94 ammo in my nuke launcher... and 8 in my gatling slugger. The moment I entered the next level I spammed slugs everywhere, most of the IDPD died shortly after exiting their portals. I fired my remaining slugs into the throne and then nuked it to death.
And so I entered my second loop with 2 health, a ton of nuke ammo, and 0 slugs. I got shot dead by a crow bandit shortly afterwards.