"An RPG about Mario? What the...?" is a natural reaction. And yet, some deranged developers at Square and Nintendo went and did it. The result was Super Mario RPG, which does, indeed, feature the pasty plumber in the leading role. What's more, he's a deaf-mute (possibly as a parody of Crono). Bowser, the Princess, and a whole bunch of other Mario mainstays make appearances as well in a highly unoriginal, yet engaging battle against some evil guy that doesn't really matter.
Super Mario RPG boasted two technical innovations at the time of its release. The first was the pseudo-3D environments of the game and the various action elements that accompanied them. Mario runs and jumps almost as much as in the platform games - in fact, doing so is imperative to getting through most of the dungeons, despite the fact that the battles are conducted in traditional RPG style. The second innovation merges action elements into the actual battling. For instance, pressing certain buttons at certain times strengthens the effect of whatever was being done, be it an attack, a spell or an item. (This was reused later in none other than Final Fantasy VIII.) Despite the thoroughly deliberate badness of the plot and the mediocrity of the soundtrack, the colorful, cartoony pseudo-3D environments are actually engrossing. The true strength of the game lies in all the pointless but fun diversions - there is a whole slew of bonus games, bonus stages, bonus battles, little secrets and little puzzles that make the playing time worthwhile. The fine dungeon design helps too, as does the minor puzzle element.
The game contributes absolutely nothing to video game storytelling and breaks absolutely no new non-technical ground. Its creativity and its value lie in the details. Overall, one play through Super Mario RPG is a good enough way to kill some time (as is a bit of Lunar), but the addictiveness of the gameplay, unfortunately, diminishes greatly with subsequent plays. That, however, could only be expected with a storyline this cheeky.