Actually, Link is able to get sword and shield upgrades on most of the games. The games exclude OoT and the FS, and possibly AoL (Adventure of Link). Actually, I think Link had a level-up system in AoL. Looking at that and seeing as AoL had a battle mode in the overworld, AoL has more RPG elements. Reality, the definition of "RPG" is vague at best. But even with that, we know that Luigi's Mansion is definitely NOT RPG.