Two single player games at once for me, which is uncommon.
Metroid Dread (Dread difficulty) - This is the one hit kill mode. I'm on the final cleanup now. One hit kills has made me appreciate how well designed all the bosses in this game are. Timing is sometimes strict, but there are consistent strategies for every encounter. The longest a boss has taken me is around an hour, against the creature that blocks the heat flow prior to getting the Screw Attack. Probably died to the ground laser the most as you need to follow it closely enough so that you can jump to the other side when it briefly stops crossing the room, the timing for which changes every time he uses it and ofc the floor is a kill except for the (also variable) narrow safe spot he leaves behind.
My biggest enemy so far has been the levels really. There's a lot of silly stuff that can kill you instantly, from dozens of pellets shot out from enemies, to big aoe explosions, to chargers you basically have to parry or panic dodge. Worse than all that though is Samus' own abilities. I feel like I've died a hundred times for ledge grabbing when I don't want to.
Regardless, I've still had a fun time with it and recommend Dread mode for anyone looking to squeeze more out of the game. Not quite as fun as the no hit mode in Muramasa: The Demon Blade, but it's still a good time.
Also finished
Shin Megami Tensei V: Vengeance today (100% chievos, so NG+6).
Wrote a very long post in the OT sharing my thoughts.
Castlevania: Order of Ecclesia
This is a bit more challenging than Symphony of the Night. The crab boss has kicked my arse a few times!
The Giant Enemy Crab(TM) is a common roadblock for new players, even experienced Castlevania players. The strat will come eventually.
Glad you're liking the game(?). I'm one of GAF's self-proclaimed biggest simps for Ecclesia. I think it's the best.