YMMV / Megami Tensei

• Demonic Spiders: The Succubi and the Nasu in the Corridor of Mazurka usually attack in groups of six to eight, and inflict status ailments like Paralysis and Petrification. Plus they seem to appear constantly, and they can't be recruited (preventing you from getting rid of them in the future just by having one in your roster). Even if you get to a level where they become more like Goddamn Bats, it's tedious to fight them except (and perhaps even then) on auto.
  • Even worse, Mazurka is home to Loas and Vampires, who, while they never attack in large groups like the Nasu and the Succubi, have a "smile and laugh" attack that permanently reduces your experience levels. Loas also like to spam a spell that saps away at all your party members' MP.
  • The Sea of Flames has Black Knights. They don't have any particular special attacks, but they attack in large groups, take a lot of punishment, and seem to be one of the most common enemies.
• That One Attack: Lucifer, the final boss, gets two. One is a physical attack that deals over 100 HP of damage to your entire party and it's his main attack, which is a big deal in a game where your strongest healing spell can only target one party member at a time. The other is a "curse" that will kill one member of your party. It does miss most of the time, but this is a game where there are no revival items, only a revival spell (good luck if you only have one party member who can use Recarm!), and don't forget We Cannot Go On Without You. You'll be praying he uses his third and weakest attack, Bufudyne (if you're playing the remake) or Breezaton (in the original), but of course it also seems to be his rarest move. Or that Lucifer wastes a turn trying to heal himself ...that is, if you remembered to bring the White Dragon Gem.
• That One Level: The aptly named Sea of Flames. On top of floor tiles that turn you around, some of the strongest enemies in the game, lots of dead ends, and a Save Point that's placed frustratingly far from the Healer (if you're playing the remake), your Health Points are drained constantly while being there. In true RPG fashion, there is an item, the Robes of Izanami, that negates the effect...but you won't find it until you're more than halfway in and to get it you have to solve a true Guide Dang It! puzzle in one shot. On top of all that, you're stopped from backtracking to Mazurka about halfway in (there is a goddess statue that will teleport you back to Bien, but it's not easy to find), and it's the only section besides the first, Daedalus Tower, you can't fly to with your mobile base Bien.
• Sequel Displacement: Even after the Persona series made Shin Megami Tensei much more well-known outside Japan, with Shin Megami Tensei I and II enjoying acclaim and attention from non-Japanese gamers, Megami Tensei still suffers from this, with even hardcore fans often tacitly treating Shin Megami Tensei I or, much more rarely, Megami Tensei II as the "true" beginning of the franchise. Early-Installment Weirdness is surely to blame, although admittedly Megami Tensei just doesn't have the same reputation as its follow-ups, with even one person involved with the English fan translation saying Megami Tensei is "not very good." Even Atlus considers SMTI to be the franchise's start, though this might be because of legal reasons (DDS characters belong to the author Aya Nishitani and he is still alive).