there's a few more endings, like the cognitor ending, secret ending, revived ending, and crimbo ending, just letting you know.
revived ending happens when eliza dies from actual damage, like electrocuted from shock collar, crimbo ending happens when you interact with the gift box near the exit ladder when it spawned and then lose to mama crimbo, cognitor ending happens when you equip the cognitor mask, capture slave, get full set, and then interact with the circle thingy on the ground, I forgot about the secret ending , remind me so I can check later. Or if you wanna ask for details
the stones (the diamond shaped thing) is an attack rune or something, I forgot the name. It can be used to damage and kill enemies by holding your attack button until you see the charging animation with black particles. Each hit deal 1 damage. You can also get an equipment that will make your basic attacks deal damage, like the claw, the knuckles, the boxing gloves, etc