When someone asks me what actually links the Final Fantasy games together I tend to answer with a list of similarities. Turn based combat systems. Magic. Summoned monsters. An epic storyline. A guy named Cid. Chocobos. Challenge bosses. Side quests. Mini-games. Magical crystals. The same sets of spells. While playing Final Fantasy VII recently I've been thinking about the mini-games part and how there seemed to be an awful lot of them. And then I tried to think of mini-games from any other game I've played so far in this marathon and only managed to think of a single one: the sliding tile puzzle in the original Final Fantasy which was more easter egg than legitimate mini-game. (It turns out there's a memory game easter egg in FFII as well?) Maybe you could count the battle arena and the multi-party Mog combat in FFVI but those feel more like extensions of the regular combat system than an actual mini-game.
Why would that be? I think mini-games are a fundamental aspect of Final Fantasy games but they didn't even exist at all until FFVII? What happened? I think the big revolution that let them start happening was the switch by Square from the Nintendo series of consoles to the CD based PlayStation. The Nintendo 64 (the comparable system at the time) had a cartridge size from 4MB to 64MB. A CD for the PS could hold 700MB and games could easily span multiple CDs. FFVII came on 3 disks. FFVIII and FFIX each had 4 disks. You can have a lot more stuff over 2800MB than you can have crammed into 4MB. This is what made the awesome FMV sequences possible but I'm thinking it's also what allowed mini-games to flourish as well. FFII was going to be ported from Japan to the US but they couldn't find space in an NES cartridge to fit an English translation. They were having to rewrite from scratch when the project was cancelled in order to do FFIV instead. I can't imagine them finding space on the FFVI cartridge to fit in a snowboarding mini-game when they couldn't find space to include vocals for their opera scene.
FFVII has been absolutely inundated with mini-games. It certainly helps that there's an actual arcade in the game that could be used as a logical place to replay the mini-games but it's felt like I couldn't go a dungeon or two without hitting one. Snowboarding, motorcycle combat, attack subs, rock-paper-scissors boxing, basketball, whatever the heck Mog House is, tactical combat at Fort Condor, triangulation digging, a shooter roller coaster, the battle arena, and most importantly chocobo raising/racing. On top of that there's a ton of one-shot mini-games where you have to press buttons at the right time in the right sequence. Also body heat management, kicking barrels at Aeris, a lot of the cross-dressing stuff, the Shinra parade, and CPR.
The sheer number of such mini-games has felt a little jarring at times, especially compared to the none at all from previous games, but they give a ton of diversions along the way. I'm on disk 3 and close to finishing the game except I haven't done anything with chocobo racing or the battle arena. I haven't yet decided if I want to just go kill Sephiroth soon or if I want to do the chocobo stuff first. I've raised a gold chocobo in the past so I don't feel a pressing need to do it, but I remember it being fun...