Sony has whipped the wrappers off of echochrono (working title) for PSP, a brand new spin-off of echochrome - the Escher-like puzzler where shifting perspectives make minds melt.
Echochrono's based around the same idea, but introduces the "new" concept of self co-op, which entails working with your own ghosts to clear a level. That means added puzzle mechanics that can't be solved alone; moving objects, doors with switches and crumbling floors all get a mention.
Each time a level is restarted a new ghost appears, and there are around 30 puzzle types to conquer. Action will be spread over nine themed worlds and there will be around 45 levels, with more added later as DLC through PSN.
The first batch of echochrono shots show a coloured world that appears to be two-dimensional, and not a rotating 3D affair like before.
Echochrono is due out this autumn/winter.