The GDC has quite a hard job. They have to create a game that is visually appealing, and has different levels of difficulty built within the game. This allows the rookies all the way up to the veterans from 1992 to have fun and enjoy the game.
Yes, this years game may seem boring in terms of diversity as many robots look like boxes, but have you had a chance to see all the robots up close? I think if you were to look at every single "box bot" you would be surprised at how diverse robots this year really are.
Some examples of this: kicker style (motor, pneumatic, spring, electromagnetic, etc), drive train choice, hanging method, etc.
This game also posed several design challenges that you might be overlooking as well. Want to go under the tunnel? You had better be shorter than 17" or it isn't happening. Want to traverse the bumps? Hope you shock mounted everything.
There are so many more things that are hidden within this years game that most people just overlooked. Strategy wise, yes, there are "few", but this all changes when you place in things like the ranking system for quals.
I applaud the GDC for this year's game. It made me personally think even harder this year about design trade offs, something that happens in the real engineering world.