In the Overview section on a map, if you click the Game type attribute, the search results will be for maps with that tag.
Also, if you search for the tag in the standard search, most of the time, the result will return a match too.
@raspatan: I've come across some minor incompatibilities in Windows too, but they aren't too common. One example is Q3 Fortress crashing when toggling fullscreen in-game.
Making the environment interesting would be the hard part. Maybe clouds and buildings could be used to make the environment interesting.
Maybe you could have a game mode where one player could not die and needs to get from one side of the map to other, then the sides are swapped. The player that makes it the furthest wins. I guess there could be other game mechanics too.
Anyway, it was nice to think about a possible mod over lunch, thanks!
As to any existing mod with a Jetpack, there is none that I'm aware of.