You can't do literally every thing in the game solo as a BLU, and in some people's minds that makes it a lie. Lol great logic.

Designed for solo play means that you're going to be spending a lot of time in the Masked Carnivale puzzling out the challenges and bonus achievements. If you play through all 25 stages of the Carnivale, using the different strategies available to defeat enemies on your own, you will see that it has literally been designed for solo play.

That doesn't mean you get to solo Kefka savage.

I mean come on, give me a break.