Overall Balance. I dont like when the final stages of a game get too easy. See Altima on FFTatics. See SMT IV: at advanced points you can almost insta-kill even bosses. Its like the devs didn't predicted that player would make wise use of the mechanics (like skill heritance to fuse OP demons). The result? Final battles were a pushover, which ruins for me the sense of danger and challenge - always necessary in any battle. I remember even today my battle with Ultimecia in FFVIII because was engaging. When final battles are easy, the game for me ends partially on a bland note. And it seems more and more usual nowadays, with some exceptions - Nyx Avatar (P3), Izanami (P4),Caius and Bhunivelze (FFXIII) . Also, not interested on need-to-grind impossible battles. Its a lot different from challeging battles.
Bland soundtrack. Or worse: devs, trying to impress and please everybody, so they pick up the most generic song choices or trend "genres". See:
FFXIII-2: OST without coesion at all. Although Caius Theme is one of the most memorable FF songs in a long time since the departure of Nobuo, it falls off place when next we're hearing electronic woob-woob and then scream with guitars (which I hate more than anything). If theres a dev choice to put lots of genres in game, it has to be really well executed and meditated to work, or else will seem like is trying too much to appeal everybody.
The new DMC: the worst soundtrack I ever heard. Ininteligible noise and "dubstep", cuz it was trend. Is not a song choice made because it makes a union with the game thematics; its to please players and demands of market. Most of time songs didn't fit the circunstances. Maybe the problem is not even dubstep, but just the that songs were plain bad. But why to put such a genre? Of course, because was trend, but not executed on a good way. Its never good put something just cuz is what everybody is talking about if what you'll deliver is a generic version of that thing.
Oh yeah. What I despise the most are things in a game made just to please the market. Rarely something good will come to light. Most of times, generic stuff. See FFXIII trying to make a "ocidental RPG". Of course, they cannot totally ignore the needs of public, because we're talking about industry, but.... Thats why I love RPGMaker, we have a lot of freedom (not restrained by deadlines, more freedom to explore themes forgotten by industry in general, etc etc). And under this topic: way females are represented. Intending to appeal the male players (unfortunately the major public), we see absurd armor design just to show unreal big tits and etc. Or Damsel in distress: women can never do things on their own; their role is either dying, sacrificing themselves so male hero can proceed, secondary bland roles, being rescued etc - which is the major flaw of FFTatics: more of 50% time the plot device is rescue-that-girl. I'll not even enter on LGBT matter, like: you HAVE to date a girl when I wanna date that cool bearded warrior, er....... ;~~
Devs trying to add to the story things that obsviously weren't there to release more content to milk money or appeal the public. P4G and all after-P4-related games, I'm looking at you. Don't force a formula to work twice just to appeal your public. Its ruins the original game. Just move to another project, unless the idea for a sequence is REALLY good. And really good sequence, wise like the first game are rare, because or they depart to absurd new things or get stuck in the mechanism of the first game. Very hard to balance this.
Generic plots, unbelievable characters. You may say that FE: Awakening is a GREAT game. I don't agree, its a good game. Er... Ok, gameplay is cool. But the story is just... generic, predictable and silly. I mean, Chrom and the Exalt are SOOOOOO good persons, its like they're saints, always willing to sacrifice themselves for people, what is very boring and hard to believe. Believable worlds and characters: please. I couldn't proceed to keep playing Asuras Wrath cuz everything is so predictable... From the moment we see the wife of the protagonist we know what will happen (again, generic females portrait).