In no particular order, the bad gameplay from Mass Effect 2.

Coolant: they keep you from shooting forever (and thus motivate you to suck less) by having your futuristic kinetic projectile weapons dependent on cooldown. Okay, that's a real thing, machine guns get hot, you can't shoot them constantly. However, machine guns also have bullets. But not Mass Effect 2 guns. They have infinite ammo, you just can't shoot infinitely. Get it? Me either. Now, your weapons can only cool down by ejecting slices of coolant. Fortunately, all weapons, even those developed by other cultures, even invading cultures ones from millions of years ago, use the same coolant in the same form factor. So you don't have to manage different kinds of ammo. Just one kind of coolant. (We're ignoring "heavy" weapons.) And many enemies drop coolant when you kill them. Or there might be coolant just lying around. Or, in boss fights, your guns might just magically be refilled with coolant when you advance to the next fight phase. COME THE FUCK ON. If your game mechanic is so broken that you have to code in "cheating" in the boss fights, maybe you should revisit that mechanic, y'think?  (The original Mass Effect did this much better, still having infinite ammo, but also having actual cooldown on your guns, so you had to plan your shots carefully or your guns would overheat and you couldn't shoot at all for a while.)

Sudden time sensitivity: during the first two acts of the game, it doesn't matter when you do things. Even if you are told a quest is critical, you can do it whenever you want, and it only becomes time sensitive when you start it. For example, there's a spaceship that's going to crash into a planet unless you divert it. It'll wait forever for you to get there, then when you dock, you have four minutes to turn on the engines, or you lose. There's another one with missiles attacking a colony. And others with kidnappings and stuff. Okay, it's goofy for real life, but the game sets up this pattern of "quests aren't time sensitive until you start them" which we come to rely on. The game says these things are urgent, but they'll wait for you. And then Act 3 starts and suddenly, shit doesn't wait for you. Bad things happen if you don't start the "suicide mission" the very moment it is offered to you, and bad things keep happening if you keep doing other quests, no matter how important they are. OH PLEASE. How am I supposed to know it matters? "Hey, you remember all those previous times we said, 'you better hurry' but we didn't really mean it? Now we mean it!" 

New game mechanics: this is a cardinal flaw in my book. The joy of playing a game is found in discovering the rules and behaviours (the mechanics) of a new system and gradually becoming a master of that system; we like games because as humans we like to learn, and we feel enjoyment from getting good at playing them. When you spend 40 hours playing a game, you get a feel for what they want you to learn and get good at. It is bad game design to introduce new rules very late in the game, where techniques you have had no in-game training or experience in exercising can have serious consequences. It is particularly bad game design when the only other time you had to do something like that was just once in the previous game, where the outcome was irrelevant to your choice; they presented this mechanic simply in order to add dramatic tension. Now in the second game you have to engage with a similar mechanic, but the outcome is dependent on your choice. So not only is the mechanic new within the game, the only tiny bit of training we had with it in the previous game set up an incorrect assumption about how it should be played. THIS IS BULLSHIT. I'd be perfectly happy with this game mechanic if they'd made a point of having us exercise it several times earlier in the game; in fact, I would have loved it. But springing it on us in the last hour of the game with no warning and no training is absolute shit.

Resource restriction: all role-playing games have to limit resources and access to higher level weapons in order to actually be playable. You can't just give the new player the best weapon right away or it will be impossible to provide a balanced and engaging 20+ hour game with new foes and challenges. However, it really makes no sense to put the player in a giant space ship, which cost vast sums of money to create, crewed with a couple dozen people who say they are clearly getting paid very well and yet dictate that you have no money. "If you want to buy anything, you'll have to rob ATMs and rifle through people's lockers, wall safes and wallets." Yeah, this is actually a thing in the game.

Pseudo-fishing: other resource stupidity is contained in the limited supplies of four metal ores that you need to research upgrades; in order to get these ores you can't just buy them, you have to put your ship in orbit around dozens of planets (expending fuel you have to buy), manually scan with a recticle for the presence of ore, then send down a probe (that you have to buy) to collect that ore. OH MY GOD. It's just as bad as fishing in a Zelda game, except that you have to do it, probably for five or six hours, if you want your shit upgraded. It's a totally artificial mechanism for slowing gameplay down; the player can't get better at it as there's no skill to learn, it's not enjoyable, it's just repetitive, there's no creativity, no actual game, it's just a timewaster. Sometimes you'll find a random side quest in your exploration of these planets but you know what? I didn't need the motivation of finding ore in order to seek out side quests -- they're their own reward because they are the game I am sitting here wishing I could play, instead of mashing SEND PROBE for the thousandth time. Usually in an RPG, when you have to find a bunch of a limited resource in order to upgrade your shit, you at least get to play the game (kill some monsters) while you're searching. But not Mass Effect 2. 

Sigh.

I just started ME3 last night, and it seems better in some ways. The combat seems more fluid, though it is also much more intense; so intense that you are basically forced to use the "power recticle" to pause gameplay to plan your next shot, movement or action. Health management is a step back in absurdity from the basically infinite health you had in ME2 (if you hide behind something long enough, your health regenerates fully) and back towards ME1's physical health/shield power which is more game-like. Also there's apparently no more infinite mental incendiary grenades, which is good, but also bad because the fucking stupid "coolant" ammo system from ME2 is back again. I'm intrigued by the new need for weight management, which lets you balance power/magic cooldown times against physical firepower; if you're carrying lighter guns then you can use your powers more often. That's nice. 

I'm also kind of fucked because I imported my ME2 character, which was at level 29, and she kept that level. I had to reassign all my skill points, which was fine, but it also means that right here at the beginning of the game, I'm fighting "level 29" monsters, so there's not much getting acquainted time. Also, that the game allows me to do this means that all enemies are programmed to scale their difficulty to my level. Which is kind of good and kind of bad. Good in that it means the game will always be a challenge, and bad in that I will never be able to actually "master" anything like one does in other RPGs. Sometimes it's nice to just wade through the chaff in an early level when you come back to it, knowing there's challenging monsters later on, but in ME3 there's no chaff (and no coming back, either) at all. So we'll see how that goes.

Also, why the fuck can I not remove the mascara from my character? Even when I remove all makeup, there's still these huge blotchy black eyelashes.

Ugh.

Sure, I understand why people play these games, and I'm having lots of fun despite these problems. But it is very jarring, especially coming from the very tightly and carefully constructed worlds and game systems in JRPGs like Final Fantasy and Dragon's Dogma and Dragon's Quest and Dark Souls, to see such egregiously sloppy and amateurish game mechanics used to tell such an interesting and engaging story. 

NB: I suspect that if you select "storytelling" difficulty that most of my complaints (except sudden time sensitivity and new game mechanic) become kind of irrelevant because Shepard becomes some kind of unstoppable force of nature, so I can totally see playing the game that way and just enjoying a William Goldman's Princess Bride-esque "good parts" version of Mass Effect.