xenonninja
Newcomer
I was not using a magnet ring, which might have made it attainable. I got a critical hit right before killing the slime, so my guess is that the knockback somehow transferred to the item which pushed it far enough towards the wall that I couldn't grab it. This hasn't happened to me before. Steam indicates I'm on the latest version, 1.5.6, and this playthrough is single-player. This is also an English playthrough if that's relavent.