If you purchased Echoshift or plan to before April 1 you’ll get an extra seven levels as a bonus. Echoshift is similar to Cursor*10 or Onore no Shinzuru Michi wo Yuke where players use time lapse clones to solve puzzles.
The seven levels are in the Echoshift add-on levels package on the PlayStation Store right now. You can get them for free starting today and until April 1. SCEA has not announce pricing for the extra stages post-promotion. In Europe, seven Echoshift stages, perhaps the same stages, were also given away for free.