Enter The Gungeon

First step is to unlock the Robot, which is unlocked by a separate achievement.



Instead of hearts, the Robot has 6 armor, which is significantly harder to replace than hearts. To compensate, he has the Robot's Right Arm, the starter with the largest clip and accuracy on par with the Marine. For items, he has Battery Bullets (passive: accuracy boost, electrifies puddles of water with any shot, immunity to electrified water) and Coolant Leak (active: spills water in front to synergize with Battery Bullets). Finally, he has a semi-hidden passive: collecting Junk gives him a permanent 5% damage buff per piece of Junk for all weapons.

Underneath this spoiler is the preparation for actually getting to the past. Short version: Unlock Rainbow Mode, get the Re-Armed achievement to unlock Clone, blow up all non-rainbow chests for chances at Junk.



In the Robot's past, you will have your starting equipment as well as Robot's Left Arm, a chaingun. You'll be fighting Sarah Connor The Last Human. There's cover in the arena, but don't really try to utilize it, as it'll likely all be destroyed in the first 15 seconds.

She has the standard boss attacks of firing random bullets and summoning additional mooks, this time in the form of shotgun wielding humans. Her remaining attacks are a grenade salvo similar to the Convict's past, a spiral of bullets that can be easily strafed around and through, and unleashing poison that covers a large portion of the arena. Dodge rolling is the only way to avoid the poison if you're caught in it. Between attacks, she'll either try to run away from your shots or teleport.

Remember to use your blanks and Coolant Leak, as it recharges quickly and gives you a good damage field if she stands still.

There's no real trick, you just need to be persistent. There was nothing special about the run when I got this, I had several failed runs when I was much better geared up.

-Hearts don't heal. They do nothing.
-Buy armor whenever you can, even before keys.
-"Heart container" items do nothing for the robot, unless it'll give you a synergy you want, pass.
-Statues that normally take away a heart container, however, are more than happy to relieve you of 2 armor
-Guns that spill water speed up your ability to clear rooms and kill certain bosses thanks to Battery Bullets (slime or gas do nothing)
-Personally I skipped the Oubliette. I found the longer my games went, the more likely I was to get hit.
-By the same logic, on the run I was successful, when I found the Dragun room I just went for it rather than fully clearing the floor

Good luck