Warning: We're going to be spoiling the end of these games, so don't complain if you haven't played them yet.
Life is hard for a video game boss. They spend all their time in some humongous chamber, waiting for some wannabe hero to appear, hoping he doesn't find their one weak spot.
It's no wonder that some game bosses seem to just shrug and give up.
Trevelyan from Goldeneye 007
In this N64 title, considered one of the most important shooters of all time, Bond finds time between martinis to thwart ex-agent Alec Trevelyan's plan to send the country which betrayed him back to the Stone Age. The game is so highly regarded due to its balanced death match options and working stealth sections. It is also because of developer Rare's decision to dehumanize the enemies by showing them as square-headed freaks, thus letting us step inside Bond's head by seeing them as he sees them: not as people, but as things to be destroyed.
What you'd expect ...
In the movie, Trevelyan acquitted himself pretty well, holding his own against Bond in a straightforward fist fight. How will this be recreated in a first-person shooter? Will you have to keep pausing the game, thus causing Bond to raise his arm in front of his face to deflect Trevelyan's blows? Will you have to karate chop him to death? For England, James?
What actually happens ...
The game deals with these difficulties by not actually including badass Trevelyan as a character. He is replaced with "little girl" Trevelyan, who runs away from you, throwing up a wall of henchmen as he does so. He also has the audacity to imply through one-liners that running away from Bond makes him the braver man.
Trevelyan climbs, sobbing with terror, onto a ludicrously small platform. You, as Bond, follow him down and kill him. End of game. Trevelyan is dead.
But, the whole thing was like killing a child, and instead of triumph, there is a feeling of gnawing emptiness that can only be sated by more death. Perhaps, Bond won't jump on the helicopter after all. Perhaps, he'll stay here and die with his ambitions.
But, no, James is rewarded for his defeat of this frightened, helpless man by getting the girl (the same one whose ass you had to protect in the most tedious parts of the game) and we watch as they kiss with their weird, square heads.
Of course, this is James Bond we're talking about, who "gets the girl" about six times on an average day. So, for Bond it must have been the reward equivalent of a snack-sized bag of Cheetos.
Giant alien brains from Gradius series
The Gradius series is truly old school. The original was released back in the NES days and had sequels and spinoffs aplenty, all the way up to Gradius V in 2004. The games are all 2D side-scrolling shoot-em-ups (or "shmups" as you should definitely not call them in front of girls), which will have you dodging slow-moving enemy bullets and collecting power-ups to enhance your own weapons as you navigate your spaceship through some pretty strange shit.
Above: Pretty strange shit.
What you'd expect ...
Let's say you're playing Gradius V, and you're enjoying it despite the fact that the damn thing is trying as hard as it can to make you fail. Seriously, if the game's packaging included a little trap that tore your hands off the first time you opened the box, it couldn't make it more obvious that it hates you. Let's say that, hands intact, you've made it to the final level. Given the bosses you've faced down so far, you'd expect something pretty fucking hardcore like some screen-filling badass whose very glare will terrify you into surrender. It's a balls-to-the-wall, glistening, squishy boomstravaganza, with maybe a pixel's width of the screen at a time not occupied by the bullet storm your foe will let loose at you from his unimaginable maw.
What actually happens ...
Considering how enthusiastic all the henchmen you've slaughtered have been, the evil alien overlords of the Gradius universe are surprisingly unmotivated. You can forgive them for not having much energy. After all, they are pretty much just brains.
But damn, guys, stick a gun turret or something in the room with you. A TV or something, maybe if you keep yourselves entertained you won't end up so goddamn depressed by the time we reach you. Sometimes you don't even have to get a shot off; the brain sees you in the room and explodes out of sheer desperation. The only way to lose against these boys is to intentionally fly your ship directly into them. And you have to do it fast, since they decide pretty quickly that they're better off dead.
The end bosses in Gradius II and III at least get a few shots off, but we get the feeling it's more to spare their dignity than anything else. They can meet up with the end bosses from Gradius I, IV and V in Evil Alien Heaven and say, "Well, at least we tried."