Re: escort missions: I got one in Morrowind. The destination was just south of another town. I talked to the fast-travel (silt strider) bloke and all his prices had slightly more than doubled. I paid for both of us, and there we were. Two-minute mission.
I never could stand fixed cameras or flying cameras beyond Monsters and Killer Gorilla.
The fricking dark. If I don't want to be able to see what's going on and occasionally get hit, I'll pay some nice lady in leather underwear to blindfold and spank me.
Idiots. The playing kind and the computer-controlled kind. Teammate / escort-mission client / soldier is standing on a bench, unsure how to get down, or is running along the slope, sliding down, running back up to where he started, running along the slope, sliding down et cetera ad infinitum because he's got it into his simulated head that he needs to reach the other side of the slope to run down from there to me, or UNMC nut runs ahead, alerts the Covenant to our presence, comes back and shines his torch right into my face.
Also: failure to communicate. Some NPCs you just can't reach, like a guard who was very happy to see me and therefore stood in the middle of the bridge to chat to me. If he'd been less pleased to see me, he'd have gone to one side or the other to get by and I wouldn't have been stuck.
Ridiculous health levels. Sorry, can't do anything. Enemy medic survived direct hit from artillery shell and regenerated to full in 2 seconds.
Seemingly unlimited numbers of pointless, brainless little bits of **** nibbling at me. Oh look, a skirmisher ... dead. Oh look, a skirmisher ... dead. Oh look, a skirmisher ... dead. Oh look, a skirmisher ... dead. Oh look, a skirmisher ... dead. Oh look, a skirmisher ... dead. Oh look, a skirmisher ... dead. Oh look, a skirmisher ... dead. Look, really, **** off with the skirmishers or stop sounding the alarm every time one shows up or something. Oh look, a rat ... dead. Oh look, a rat ... dead. Oh look, a rat ... dead. Oh look, a rat ... dead. Damn you, I'm level 12. They can't touch me. Can we just not bother showing them any more?
Lies. "Put some clothes on before you attract the wrong kind of attention." There is NO such wrong kind of attention programmed into this game. "You could get arrested for that. Put something on." You can't get arrested for it.
(They're a bit weird about it anyway. A shield or a ring or a necklace is enough to count as "not naked" in that game.)
The rainbows and bubbles and pretty lights could work. You could have Sister Claire bubble-boys in blue, bleeding blue bubbles when injured, pink faeries that shed glitter when you hit them, white unicorns, green nymphs that emit sprays of flower petals instead of blood, red ... er, something, and purple, erm, something that something, ... and be trying to either take over a faction and lead it to victory or restore balance to the world. Restoring balance by always siding with whichever faction needs it most and taking on whichever's doing too well would make for awkward moments. The grey-brown-loving grit fans could have their little brown toads with grey weapons leeching colour from areas they control and feeding on the deaths of the bright ones. There could be fires and weeds and floods waiting to rampage if their corresponding good aspect of a colour got too strong and the other good aspects couldn't contain the bad aspect any longer, and MMO would be a nightmarish battle between the imbalanced fairy and unicorn brigades of barely-pubescent girls with rooms full of My Little Pony and the leech-toad-worshipping Linkin Park and Nickelback fans with bedrooms painted black. If the toads get too powerful, you get CANE toads. You could play as a songbird-knight. One of the nastiest creatures in the game would be a magpie.