Originally, I was going to write this as a guide to GMs who wanted to improve their games the "Perko Way". But... it's too weird.
The basic thing that most beginning GMs do wrong is pacing. Except that pacing is a term for a linear, passive media, like books. The whole idea of pacing is, I've recently decided, totally wrongheaded for games. Especially tabletops.
Instead, what we want is toy density.
In a tabletop, most players seem to get the most excited when they are offered a situation which can be resolved as they see fit. It's not a puzzle, precisely, although it can be. It's... an opportunity to come up with a clever way to come out on top.
Most bad GMs make their plot situations force the players into certain paths. For example, "You discovered a map of a buried treasure and set out to dig it up!"
Whee? Why not let them decide exactly what they are going to do. Let them figure out the path they want to take. They might decide to hire some lackeys to help them dig, or they might postpone the treasure search until they have more free time, or any number of things.
I find that if you give opportunities and let the players decide how to take them, the players pace themselves. When the players want action, they'll push the opportunity towards action. When they want drama, the situation will turn dramatic. It's really that easy.
The main challenge to overcome is the need to push players. Instead of pushing, pull. I've covered this in basic and somewhat more advanced posts. Once you grok that, you can start to do things the right way.
(Grok is a great word. Some people think it's stupid or meaningless. It really isn't: it simply means "to work with or learn something until it is obviously the only way things work.")
Then you just have to get a bit of practice turning pushing scenes into pulling scenes. Each session should have at least one (preferably two or three) of these "open situations".
The last thing to master is to keep the party from being dominated by one player's skewed pacing sense.
ANYWAY, that's tabletops. Video games are more difficult.
First, there's no mob mentality. In a tabletop, the players will resonate and egg each other on.
Second, the rules are more restrictive. Because of this, players have a more passive experience. "Siezing the initiative" is almost a non-concept in games. Open-ended games (like a space conquest game) don't have distinct opportunities - they have a kind of continuum of semi-opportunities. Without any mob mentality, the natural tendency is to minmax - to abuse the rules in the most efficient way you can find. This is rewarded, while fun risks are punished.
Seems kind of silly, to me.
What if the next game you played didn't let you lose?
No matter what you did, you didn't lose. Each choice simply changed the way you progressed through the game.
It would be much more like a tabletop: it's very rare that a group of players can lose a tabletop, and if that's a danger, it's almost always very obvious. The vast majority of the time, it's a given that you will succeed, so long as you don't piss the GM off by actively being assholes.
It doesn't really matter which interesting approach you take: if it's feasible, it will advance the plot. It may advance it in a weird way, such as the entire party being captured, but it's a given that, so long as you try, you'll win.
One of the big advantages the GM gives is this "no efficiency" clause. If players are inefficient, it doesn't matter! The next situation is going to be adjusted for their current strength, so it hardly matters whether they get 120 xp or 150 xp.
Sure, some players want to be hyperefficient twinks. That's not bad at all: reward them for trying clever things. It rapidly becomes the most efficient path to getting power.
The problem is letting a computer game do this...
I like the idea of including toys which can be combined in various ways. Not simply combined to improve stats, but linked in program-like ways. The player can find and combine these toys to make cool new devices and abilities.
Now, if the game offers missions, the player can bring his toys on these missions. The missions adjust to the effectiveness of the toys, but the player is still allowed to approach in any manner he deems cool.