From what i can tell you need to get h-grabbed by enemies several times, then the animation shows up in the gallery.
Possibly you also have to get a gameover by them.
Just dying to them is not enough, though!
There is minimal UI translation but nothing about the story is understandable in the least. You don't need it either, the game is strictly linear with backtracking.
You have to equip guns and mods in the inventory to make use of them. Enemies respawn when loading savegames, and later on when going through certain doors. Farming enemies for cash is possible but dumb, as the enemies are limitless but the items (including the shops) are not.
It's not hard by any stretch, though. After a sloggy start you have 4+ ammo types with several guns for each, some amazingly ammo efficient, and you have hundreds of rounds for all of them. Plus with the exception of bosses and later on enemies with guns you don't _have_ to fight anything, just dash past. A single exception i think when "saving" someone.