[sigh] Fine, I'll give some public input if it'll make you happy. I'm going to close my eyes and type except to put in a hyperlink
or two and very minor formatting.
Think of a fairly small, closed area RPG game to start. X distance units by Y distance units. Graph paper? Note location of areas and distance from one area to the next. Standardize distance units, give units speed as distance unit / turn. Standardize the length of a turn, a minute or Z seconds, whatever. This will do the following. A.) let people somewhat choose what objectives / areas to do at a cost of speed (distance/time). Note what happens at each area on a semi script.
I'm going to use an example with mad libs.... "in space" for the heck of it. "Planet [to do: think up name] colony was founded in 5554 AD, and grew to pop 15,000 by 5583. Several scientific breakthroughs including [describe tech used in game] were found. Rumors persisted of [well contained secret experiments] on longevity. All was well [until it wasn't]. There were [consequences of it not being well anymore]. Faced with this [disaster] and worried about losing their [research] , renounced scientist turned to [well contained secret experiments], which [went wrong]. Now Planet [to do: think up name] faces [consequences of it not being well anymore] and [the no longer contained secret experiments]. You are [insert character] at [insert place and time]. You must [do something to survive]."
I
may or may not fill that in later.
So you start out with a starting point. This is Point A, the ... landing zone .... where your transport ship .... 's departure was delayed ... due to some second or third removed indirect side effect of [consequences of it not being well anymore] and [the no longer contained secret experiments]. You are told by the GM that [event 1 happened] at [location A]. Then players will use skills to either solve, defeat, hide from, or run from, the event.
You get a map of the area (remember that fairly small, closed area RPG game to start?) showing points (and you the GM keep the distances between those points on a separate spreadsheet they don't see).
Point B is a communications tower .... (47 distance units west away from from point A where you are).
Point C is a maintenance hanger (27 distance units west away from point A where you are)
Point D is the residential area (39 distance units north from point A where you are)
Point E is a residential area with a hydroponics bay (12 distance units south from point A where you are).
Point F is an armory (19 distance units East from Point A where you are).
etc etc.
This allows players to travel to different locations at different times. They each have something you planned to happen with rewards or consequences and varying challenges. You keep certain things to yourself, for example. The Maintenance hanger has overland transport that will speed the player up but also has a certain [monster(s)]. The communication tower has valuation information, including several security codes but draws [major problem they have to deal with as a challenge]. The armory has weapons and even better weapons if you have the security codes from the coms towers, etc. Residential areas have potential recruits that are poorly armed as well as civilians to rescue. The residential area with a hydroponics bay is overrun with enemies, etc etc etc.
Consider information as a motivating factor, when they have it available to them.
Consider skills as a chance to overcome the stat blocks of various challenges (HP by damage/to hit, stealth overcoming detection, diplomacy gaining bonuses from friendlies or turning only certain enemies non hostile, tech skills overriding locks, making certain bonuses happen, and counteracting bad things, etc etc etc).
Set up a story on a timeline, making the distance / travel thing all the more important, though grant some room for choices, and ways to shorten the timeline (speed up the bad guy's progress) or lengthen it (give the player more time) depending on good or bad reasonable actions. Example, if you don't save the residential area by time index ... whatever, then they will succumb to the [consequences of it not being well anymore] and [the no longer contained secret experiments]. If however you save them before time index whatever, then you will gain the following bonuses.... Also doing certain things will make various tasks easier or harder to do and thus easier or harder to avoid bad things and earn good things. Somehow figuring out the security codes will make getting the coms tower working and the armory special stash easier, which would make liberating the residential areas easier, which would slow down the bad guy. Getting the overland transit would cost time (more time) but if successful, would make future transit to various other locations/objectives faster (cost less time), but it's a risk to justify the reward and takes time.
Also, figure out the information about and how to stop the [consequences of it not being well anymore] and [the no longer contained secret experiments]. Figure out where the hidden lab is, how to access it, etc.
There I posted, once.