geomod was a nice gimmick, but it was too underused to be actually anything earth shattering
The really funny/sad thing is how, at the time, everyone was crowing about how destructible terrain was the future, how every new game engine would have to include it, yadda yadda. And here we are, years later. Yup... gimmick.
I don't pretend that Red Faction would have been a GREAT game without the distraction of geomod, but it would have been a better one. The RF team just tried to do too damn much-- develop a new engine from scratch, build the new engine around this brand-new geomod gimmick, make it work identically on console and PC, make the game appeal to PC gamers and console gamers, rip off Half-Life, implement flyable and drivable vehicles, and do it all with too little time, too little budget, and a craptacular story.
I've got a folder full of screenshots of amusing glitches in Red Faction. AIs driving upside-down vehicles. Light coronas rendering through other objects. Unlit objects against fully-lit walls. Fog that gets brighter with distance instead of darker. Clipping inside people's faces by standing too close to them. Etc...