I'll start you off..
Unreal Tournament 3
I had some hair-raising online matches with this one. Was a real shame it never really caught on. Still a very slick experience to this day (just turn off framerate smoothing).
Why was it not popular? Fast fps was already losing popularity. Art style was marmite and bloom effects were overdone - too much of a departure from previous UT games. Had a buggy release with a console-like UI (which was subsequently fixed). Took a few too many risks with new features that jarred with players. Arguably didn't ship with enough good maps.
Unreal Tournament 3
I had some hair-raising online matches with this one. Was a real shame it never really caught on. Still a very slick experience to this day (just turn off framerate smoothing).
Why was it not popular? Fast fps was already losing popularity. Art style was marmite and bloom effects were overdone - too much of a departure from previous UT games. Had a buggy release with a console-like UI (which was subsequently fixed). Took a few too many risks with new features that jarred with players. Arguably didn't ship with enough good maps.