Strategy games where winning is based on memorizing where, what, and when scripted events will trigger. It’s not strategy if I can play a level, note where the enemy forces are going to suddenly appear and what they’ll do, restart the mission, and set up my forces based on that knowledge. The *Homeworld * series of games were particuarily bad in this respect - most of the missions became much easier once you played them, lost, and then played them again knowing exactly where and when the enemy forces would appear.
Enemy AI with easily exploitable flaws. Many FPS and strategy games; once you know what the AI will do, you can exploit its reactions to win. Strategy should be about beating the enemy, not finding the holes in the programming!
Cutscenes you can’t skip. Especially cutscenes you can’t skip which take place in real time while the game is still going on, in which all your character controls are locked out for no good reason while you’re forced to watch the cutscene. Homeworld 2 is a severe offender here. I appreciate that the planetary bombardment platforms look really cool warping in from hyperspace and powering up, but I can see my fleet getting slaughtered in the background; if you aren’t going to let me do anything about that, could you at least pause the combat while I’m forced to watch the cutscene? City of Villains is also an offender here, with jarring, unskippable cutscenes in the middle of missions that completely lock out your movement and combat controls while they proceed. Half-Life 2 is one of the few games that does this right; all “cut-scenes” are fully in-game and seamless, with no loss of character control.
The inevitable “You’ve been captured, lost all your weapons, and now have to fight your way out with only this bent coathanger as a weapon” sequence. While not in itself that bad, the fact that nearly every FPS has this somewhere in the middle of the game has gotten tiresome.
Crates, that contain exactly one object, and have to be smashed open to retrieve it. That was acceptable in the days of low-resolution 2D graphics, but it’s more than a little bit silly in a 3D FPS with otherwise realistic maps and physics.
Plots in RPG or MMORPG games that require you to do something really stupid or out of character for the plot to advance. You want me to hand over the Wheel of Destruction to Azuria, who has consistently lost or had stolen every magical artifact every placed in her custody? Forget it, I can think of a dozen more secure holding places.
Deliberate time-wasting tasks in MMORPGs. I appreciate that MMORPGs are to a large degree about wasting time in entertaining ways, but getting repeated missions that are varients on “Kill 100 dire bunnies” or “Find and click on 20 magic berry bushes” ceases to be entertaining fast.