>>28036525Dragon Quest Monsters. The first one is *insanely* in-depth and has a very steep difficulty uptick once you complete the main story and start doing the post-game extra quests/boss chains.
They did a 3DS remake of it and it pains me every day of my life that they have no intentions of releasing it over here. If someone would go to the trouble of doing an english translation rom hack it would finally motivate me to hack my 3DS just to play this one game.