Unlocking minigames have their place and can be cute, but used haphazardly they become clear evidence of lazy padding. Yes, stuff like Myst or Professor Layton is obviously exempt because puzzle-solving is its entire mechanic. Otherwise? No, thanks. Thing is, very few games can properly manage swapping out whole gameplay mechanics; it's always a dicey prospect to build the majority of your game around one entire set of controls and then suddenly drop a different play-style right in the middle of it. This is also why vehicle sections are often so crummy.
There is a way to do this right, and usually it involves making the unlocking puzzle part of the main gameplay, instead of its own little minigame. The ur-example is probably the Zelda series and its myriad imitators. The puzzles are built around skills or items that you'll be using elsewhere in the game, and thus unlocking the door is also practice - figuring out how to hit five buttons at once with the boomerang will come in handy for multi-killing enemies with it later. By contrast, having to stop and play a Steampunk version of Pipe Dreams didn't really add anything to BioShock, at least not for me.
Hail Mary, Full of Exposition
Y'know who I'm sick of? The soothing, gentle-voiced, implicitly-maternal boss lady constantly keeping The Hero abreast of things via walkie talkie, Bluetooth, telepathy, whatever. Nevermind that it's overused to the point of absurdity and well beyond any level of novelty (it's no longer a big twist to have Judi Dench playing M, basically) but it paradoxically goes a long way toward reaffirming limiting gender-role archetypes: Men are good for fighting and action, women are good for nurturing and talking men through action. Blegh.
Yeah, I know, Master Chief and Cortana are supposed to have this grand, symbolic, utterly chaste (because sexuality would make him weak and her tainted) Boy Meets A.I. thing going on, but, I'm sorry, to me, it always seems like he's a giant bionic seven-year-old on his first solo hike who needs to keep calling his Mom up to tell him how to do stuff "Cortana, they've come undone, again." "It's alright, John, just repeat after me: 'The rabbit goes aroooound the great big tree ...'"
He's a one-man prophecy-fulfillin' machine!
WARNING: Contains spoiler for the movie Drive Angry.
"Destiny" is already an overused shortcut to getting an ordinary person into Hero's Journey mode, and the laziness is only compounded when the entire prophecy turns out to be exactly true ... to the point where you have to wonder why anyone bothers to do anything in these worlds without simply consulting the Big Book of Predestination first, just to see how things will turn out.
When's the last time a prophecy turned out to be wrong, or heck, even misunderstood? Even J.R.R. Tolkien, whose reverence for divinely-dictated fate was second to none, couldn't resist tweaking destiny's nose a bit. One of his major heavies, "The Witch King," charges against his human enemies with wicked confidence, partially derived from a long-foretold pronouncement that he will not fall "by the hand of man." Evidently, fine-print'll get ya even in Elvish - he falls when his last opponent turns out to be woman.