The first time you can find Metal Slimes in Dragon Quest III: HD-2D Remake will most likely be on the fifth floor of the Tower of Transcendence, which is around the halfway point of the game.

State Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China State Laboratory on Integrated ...