I beg to disagree. Most of these games weren't entirely one dimensional, and I'd say 2007 definitely had two dimensions.
2005- Stack tetras on top of goals
or place tetras under goals
2006- Shoot balls through upper goal
or deposit them through lower goal
2007- Place Ringers
or lift robots. (This game was definitely not one dimensional
2008- Hurdle Trackball over overpass
or Herd Trackball under overpass
or race around the track
2009- Put balls in Goal
Granted, in 2005 good teams all stacked. In 2006 though, 195 and 1902 rose to fame playing exclusively with the lower goal. Other teams may have too, but my memory is starting to fail me. 2007 definitely was not one dimensional, as those bonus points for lifting robots were important, and lifting robots was not an easy task. 2008, most good robots did hurdle. However, at GSR a herder (58) captained an alliance all the way to the finals, and 148 played an integral role in the RoboSimChickens Championship victory. This year, we all did the same thing though.
That said, I'd love to play another 2004-esque game.
(It seems FIRST Frenzy is quickly acquiring some sort of cult status as a magical perfect game around here...)