(This post was originally intended for the Machine City blog, but it grew enough to post here. It's theory.)
Recently I played two AAA games: "Farcry: Instincts" (FCI) and "Freedom Fighters" (FF). Both were rather fun, but both had the same basic problem: there was no real sense of forward movement. Every level was simply something that had to be done, a delay on a tortuous path with a hazy end goal.
In both cases, I didn't even realize I was approaching the last level until I was at it. (Both were also very easy except when nearly impossible, but that's another story.)
All games need a sense of forward motion. Otherwise, you're just treading water. I bought FF pretty near to when it came out, and I only just finished it. It didn't really grab me. Why? No hooks. You can't grab without hooks. Hooks are made of emotion.
You see, all motion is relative. If you're on the banks of a river, the river is moving. If you're floating on the river, the banks are moving. Similarly, you need to have the player's perspective see things going by, things changing. As with real life, the further away something is, the less impact its movement has. Trees whipping by your car make you feel fast. An endless plain with distant mountains doesn't really make you feel the speed, because the mountains don't feel like they're moving very fast.
Of course, in a game, you measure distance not in physical meters, but in emotional closeness. I'll use the term "jots", for no particular reason. A "jot" is a unit of emotional investment. Any emotion - love, hate, lust, fear, irritation.
Narrative is one things players invest in. Characters get jots. Play is another things players invest in. That new fireball spell aquires some jots because it is so effective. Audiovisual effects get jots, too: the fireball spell gets a few more jots because it has such a cool visual.
All of these things are things which can move by the player, give him a feeling of motion. But the mistake most games make is a simple one: they don't leave things behind. They only gather more things. Things don't pass, they just join up.
Let's look at the ultimate example of not leaving things behind: Katamari Damacy surely doesn't leave anything behind, right? Yet it's fantastically popular!
Actually, KD leaves lots behind. As you grow, you leave everything of your earlier size behind. You can no longer rummage under sofas for thumb tacks: now you roll up entire houses. You have left something behind.
Guitar Hero - you don't leave anything behind, do you? Of course you do: you leave the easy levels behind. You can still play them, but they no longer entertain you, save as fond memories.
Motion is not getting new things: it is getting new things and leaving old things behind.
To see relative motion, you have to see things fall aside. Characters, plot, gameplay, visuals. Anything that players can invest in. And the more jots they've invested, the more motion they will see as those things move and change.
FCI had no such motion, largely because there was no jotting going on. The only characters the player could feel any emotions for were the female "reporter" and the bastard merc. And that really wasn't very much. If FCI had pulled those characters closer to the player, then hunting and helping them could have been a sign of motion. But they were distant mountains: I didn't realize their plot had come until I hit their cliffs. I couldn't see them move.
Freedom Fighters had the opposite problem. The characters were fairly jotty - your brother, Isabella, the whiny guy, the black kid, Tatarin, the propagandist, and the traitor. All were stereotypes, but rather fun ones.
But the only character which moved was the black kid. Helping you in the initial stages, then becoming your direct advisor. That was good. But none of the others moved.
All the Russians didn't move: they just vanished. You didn't leave them behind, you just lost them. What happened to the propagandist after you raided her TV tower? You don't get to talk to her, or choose her fate, or see her deal with the aftereffects. She's just... gone.
Tatarin? Gone without you ever feeling him in person. The traitor? Barely introduced, swapped to evil, then vanished.
Your brother almost did well. But he didn't have many jots, and his demise was also sudden and empty. The reverse-demise of Isabella at the end was fun, but she was turned into a game token, and had no real character bits to show that she was back.
All arguments about the endings of these two games aside, both games needed to more carefully construct their narration. There was no feeling of motion. You need emotion and steady change to pull the player around. You can't get along with just one.
The Machine City, my game, will be making heavy use of this idea. This idea is a corollary of pattern adaptation control specific to narration, but it can, as I mentioned, be used in all areas. To feel forward motion, you need to feel the earlier parts of the game slipping away, being put behind you.
This is, not coincidentally, a major factor in virtually all of the best movies, comics, and books. Think of your favorite ones. I can show you how they left things behind.
Bad movies, games, and books also have these features, but they generally only have one or the other. Both emotion and motion are needed. You can't have only one.
Think about a piece which was technically superb but you didn't much like. Can you see a notable lack of one or the other? Usually, you can.
Pattern adaptation control measures jots, and uses those things to make the player feel motion. It focuses the game on the things the player notices, and makes those things even more noteworthy. The rest is background fluff, although for another player, the situation might be quite the reverse.
A fun way of looking at things, and hopefully helpful to you.