Firefall is a big one that revamps several core areas of the game based on player feedback. That includes multiple frames seeing a large-scale revisions. Designers Justin Hanson and John Deshazer elaborate upon some of the changes wrought upon the Engineer in the newest video, explaining that the class had some serious problems before -- it wasn't mobile and generally wasn't considered desirable within group composition because of its limited utility.
Meeting the new and more functional Engineer will turn that impression around. Engineers have gotten a new weapon that ramps up in damage as it scores repeated hits on a single target. They've also been granted a number of better build items, such as mini-turrets that can be tossed in odd locations and instant-build forcefields. And that's just a sample of what the milestone is improving in the game, something detailed in two recent development blogs outlining the philosophy behind the changes and what players can expect after the dust clears.