Way too many, honestly;
- Microtransactions. I can't believe no one has mentioned this one yet. My biggest grievance and the reason I almost permanently stopped playing games in general. I hate this so much, especially when developers attach it as a shortcut to in-game progression. Hell, even for cosmetics and stuff, I think it's extremely greedy.
- Downloadable Content (DLC). I'm pretty old school when it comes it gaming, but I've always had a problem with DLC. I'm not talking about artbooks, comics and soundtrack, I think those are totally fine, I'm talking about new levels, new areas, new characters. I just think it's pretty lazy and money hungry of developers not to include it in the base game in the first place and release something small much after the release of the actual game. Overall, just seems lazy like an after thought.
- Multiplayer only games. Basically the developer digging their own grave with their game. Once people stopped caring about a particular multiplayer only game, that's it. It's unplayable. You won't be able to play with others, and even if there are others that play, it will be an absolute chore to find other people. These games go on sale so often as a last ditch effort to potentially get people to play or interested.
- Bad camera angles. Yeah.... pretty obvious. Others have mentioned it as well. Games like Super Mario 64, and some others I have played have caused me no end of grief with their terrible camera angles.
- Chat functions in games (both text and voice). Honestly, let's face it - it just doesn't work. You can't trust people to be nice and kind and mature online EVER. There's no point to them and people just use their anonymity to blast and roast each other. You're better off just using Discord for it. Quick chat is probably good enough. The last thing I want to hear is some pre pubscent kid swearing at me, thinking they're cool.
Everyone else did a great job covering most of mine.