Aren't you guys being a little harsh? Akiba's Trip is certainly no Portal 2, but it's not just a fanservice game either. It has a lot of interesting ideas and a surprisingly serious story. Most of the complaints I've heard are technical in nature (load times, slowdown when lots of enemies are on screen, etc). Otherwise the only games that beat Portal 2 are Dead or Alive, some Monster Hunter spinoff thing, and Gungnir. Dead or Alive is a pretty shitty franchise but it's popular in the west too and people need something to play on their shiny new 3DSs. Monster Hunter is...Monster Hunter. I'll never quite understand why, but that franchise is basically Japan's Call of Duty. Gungnir looks quite good, though.
Does Portal 2 deserve better? Certainly. But consider that first-person games in general are not popular in Japan. And let's see how much staying power it has before jumping to conclusions.