Streamlining

Game series, like books, movies and anything else forcibly serialized, suffer from oversimplification as they are re-iterated according to the good old core business principle of pandering to whatever's assumed to represent the target consumers' tastes.

Say a startup developer makes a good game. They are then approached by the usual walking money piles with no idea of the products in which they're investing. Having no idea, these turn to ever-skewed statistics, customer feedback and the most destructive force in mass-consumer entertainment, the focus group. This excludes any consideration of the countless game elements whose effects players barely notice while in-game. It's observed, for example, that players spend inordinate amounts of time farming gear in MMOs. You then create so-called MMOs revolving around gear-farming. 'Extraneous' features are implemented as separate minigames if at all.

The pattern is of course, older than WoW, and most easily seen within a single series. The sequel's never as good as the original, is it?


Dune 2
The game which defined RTS. The original Dune game was a mix of adventure gaming and very slow real-time strategy. To this day i can't think of anything that managed the same combination. Dune 2 got pruned down to only the combat, sped up to the ridiculous button-mashing speeds we've come to expect from micromanagement games pretending to be strategic.

M.A.X. 2
The original was a turn-based strategy game forcing much foresight and planning, with weapon range and unit positioning often being much more important than damage, and supply chains playing a critical role. The sequel removed the individual unit ammunition and much of the need for interdependence, the careful logistics-heavy trench warfare which made M.A.X. unique and moved it closer to, again, the button-mashing RTS typique.

Uprising 2
In contrast to the first two examples, Uprising was one of the most hellishly demanding multitasking games ever made. I say multitasking and not micromanagement because the challenge was not cycling through units to give each the same command but keeping track of all the developments on the battlefield. At the same time, the player, piloting a tank in first person while keeping track of resources as in any RTS game, might need to strafe down an approaching tank squad with maximum power to weapons systems, then switch to defensive mode and order some tanks in to hold the line, order an orbital strike against a reinforced enemy position, pause to look at the map then switch to full engine power and zoom across the field to order an interceptor squad to take care of approaching bombers then rebuild whatever got destroyed while holding off whatever ground forces the AI teleported in while... well, it was hectic, let's leave it at that. Uprising 2 needlessly simplified the Wraith, the player's unique tank and created linear goals to follow, pretty much removing the whole scatterwhelming charm of the experience.

Heroes of Might and Magic 5
The charm of the HoMM series was its RPG feel. Because of the TBS mechanics, this didn't mean storyline for the most part but atmosphere delivered through countless little one-liner popups. Removing them and simply floating up the "+5 ore" messages was a step in the wrong direction. So was the limiting of player choice in terms of creature dwellings and hero abilities, when compared to the much more diverse HoMM 4. They tried to make it more of a pure strategy game, but only managed to lose the point of the original TBS/RPG mix. Nobody played any iteration of HoMM because it was balanced and challenging. You played it to build up your personalized hero at a hovel you turned into a monster metropolis and give him an army of enough vampires to bat out the sky, then bleed the world dry! The personal touch was crucial, and largely abandoned.

Diablo 2
Diablo 2 was focused entirely on gear-farming. That's what made it addictive, a proof-of-concept of the marketability of slot-machine gameplay.
In itself though, the game lacked much of the charm of the original, because it lacked contrast. When everything's magical, nothing is.
Getting Arkaine's Valor or a magic ring in Diablo was a big deal. It was memorable in a way that not one of the endless thousands of items in D2 ever matched. D2 trivialized every action through endless redundancy. Mana regeneration, lifestealing weapons, skill trees with obvious 'best' choices, each item more magic than the last, it was the absence of all of this, the fact that you spent the whole game conserving mana and got through half of it with non-magical gear which made Diablo so captivating. The slow start which got thrown out when making the sequel was necessary to put the endgame rush of power in perspective.

There are also exceptions to the oversimplification rule of course. I'll just give one example.

Sid Meier's Alpha Centauri
This is an offshoot of the Civilization series and it seems like something the creators were permitted to do by their purse-string masters sort of on-the-side, a shamefully (to the business mindset) creative project before cranking out Civilization 3.
Though the civilization games really shine as pure strategy, SMAC dove into storytelling, just shy of outright roleplaying. The futuristic setting of terraforming a planet orbiting Alpha Centauri is used to play out scenarios familiar to many scifi fans and cited in the game manual as inspiration: a mix of Herbert and Ransom's Pandora series and Kin Stanley Robinson's Mars books. The seven playable faction leaders had personalities and individual backgrounds worthy of any RPG campaign and the discovery of the planet itself and the ultimate fate of humanity gave finishing a match an unequaled thrill among the rather sedate TBS genre.
Game mechanics followed suit, giving the player the ability to terraform to his heart's content while customizing units using modular designs, and balance be damned. You could build an aquatic empire and sink the landlubbers to the deeps, build a mag-tube network across entire continents and instantly shuttle your tanks wherever you want them, tame native wildlife and eat your enemies alive, raise an entire mountain range to put your rival in a rain shadow and starve him out, take to the skies in antigrav flying fortresses, support your whole economy from orbiting farms and solar power accumulators or if you really wanted to throw a tantrum, you had big enough bombs to literally blow a hole in the world.
It was global conquest done your way.